WTW
WTW SenTix 41 pH Electrode with Temperature Sensor, Gel Electrolyte, DIN Connector, 103635
Measuring pH in wastewater, aquariums or swimming pools should not depend on a refilling routine. The WTW SenTix 41 features a plastic shaft and a gel electrolyte which, according to WTW, is not refilled. The electrode is low-maintenance. The pH measuring range extends from 0 to 14, and it can be used at sample temperatures of 0 to 80 °C.Gel electrolyte and fibre junctionThe shaft is made of PPE/PS, is 120 mm long and has a diameter of 12 mm. The membrane is cylindrical; its resistance at 25 °C is less than 1 GΩ. According to WTW, the fibre junction prevents blockages. There is no need to monitor or top up the electrolyte level. If the electrolyte is meant to be refillable, the SenTix 51 and 52 with liquid electrolyte and a ceramic junction in a plastic shaft are the alternative.Connection and temperature measurementThe SenTix 41 has a permanently attached 1 m cable with a waterproof DIN plug (DIN 19262). An NTC temperature sensor (30 kΩ) is built in and measures the sample temperature; it is connected to the 4 mm banana plug. The gel electrodes in this range differ in plug, cable length and temperature sensor. You should therefore establish which input the measuring instrument has before placing your order.Typical applications according to WTWWhen taking samples from water bodies, at the edge of a pool or from a wastewater pipe, what counts is an electrode that is quickly ready for use. WTW names the following media for this series:Electroplating effluent, industrial wastewater and wastewater in generalAquarium and swimming pool waterGroundwater, lake water, surface water and seawaterHousehold cleanersStorage and careBefore the first measurement, remove the wetting cap; gas bubbles behind the membrane can be removed by shaking. For short measurement breaks, immerse the electrode in reference electrolyte (3 mol/l KCl, Ag+-free). Overnight and for longer periods, it stays in the wetting cap, filled with the same electrolyte. According to WTW, storing the electrode dry or in deionised water can cause permanent damage. If the cap has dried out, the electrode needs at least 24 hours in reference electrolyte. As with any pH electrode, strong acids and alkalis, hydrofluoric acid, organic solvents, oils, fats and proteins shorten its service life.Technical detailsTypepH electrode, analogue, gel electrolyteShaft materialPlastic (PPE/PS)Shaft length / Shaft diameter120 mm / 12 mmElectrolyteGel, non-refillableReference systemSilver/silver chlorideJunctionFibreMembrane shapeCylindricalpH measuring range0 to 14Temperature range0 to 80 °CMembrane resistance< 1 GΩ at 25 °CTemperature sensorNTC 30 kΩConnectionDIN plug (DIN 19262), waterproof, and 4 mm banana plugCable1 m fixed cableScope of delivery1 WTW SenTix 41 pH electrode with wetting cap1 m fixed cable with DIN and banana plugs, permanently attached to the electrodeAccessories and procurement serviceReference electrolyte KCl 3 mol/l for the wetting cap and buffer solutions for calibration are also available. Enquiries regarding other SenTix models or larger quantities go through our procurement service.
WTW SenTix 81 precision pH electrode, glass shaft, refillable, 103642
WTW lists a wide range of applications for these glass electrodes: from diluted acids and emulsions through to beer, milk and fruit juice, right up to serum and urine. The WTW SenTix 81 features a glass shaft, a refillable liquid electrolyte and a platinum wire junction. It measures from 0 to 14 pH at sample temperatures of 0 to 100 °C. An NTC temperature sensor (30 kΩ) is fitted.Platinum wire junction and conical membraneThe glass shaft is 120 mm long and has a diameter of 12 mm. According to WTW, the platinum wire junction ensures optimum electrolyte flow without blockages. The membrane is conical in shape; according to WTW, it is impact-resistant and easy to clean. The membrane resistance at 25 °C is less than 600 MΩ. The reference system is 3 mol/l KCl, Ag+-free and refillable. According to WTW, the liquid electrolyte enables fast response times.Typical applications, according to WTWDiluted acids, salt solutions, emulsions and suspensionsCooling water, dye solutions and electroplating bathsDrinking water, groundwater, swimming pool water, lake water, surface water and seawaterSoil, paper and coffee extractsBeer, lemonade, fruit juice, vegetable juice, wine, mineral water, milk and vinegarHair dye, mouthwash and household cleanersEnzyme solutions, gastric juice, infusion solutions, protein-containing liquids, serum, Tris buffer solutions and urine (pharmaceuticals, biology, medicine)ConnectionThe SenTix 81 has a permanently attached 1 m cable with a waterproof DIN plug (DIN 19262) and a 4 mm banana plug for the sensor. The variants in this series differ only in terms of plug, cable and temperature sensor; the electrode itself is identical. The choice therefore depends on the input of the measuring instrument. If a longer shaft is needed, the SenTix 91 has a length of 170 mm instead of 120 mm.Refilling and storageThe refill opening remains open during calibration and measurement. A dropper bottle is included, according to the WTW instructions. For short measurement breaks, the electrode is immersed in reference electrolyte (KCl 3 mol/l, Ag+-free) with the refill opening open. Overnight and for longer periods, it stays in the wetting cap, filled with reference electrolyte, with the refill opening closed. According to WTW, storing the electrode in a dry state or in deionised water can cause permanent damage. If the cap has dried out, the electrode needs at least 24 hours in reference electrolyte. As with any pH electrode, strong acids and alkalis, hydrofluoric acid, organic solvents, oils, fats and proteins shorten its service life.Technical detailsTypepH electrode, analogue, liquid electrolyteShaft materialGlassShaft length / shaft diameter120 mm / 12 mmElectrolyteKCl 3 mol/l, Ag+-free, refillableJunctionPlatinum wireMembrane shapeConicalpH measuring range0 to 14Temperature range0 to 100 °CMembrane resistance< 600 MΩ at 25 °CTemperature sensorNTC 30 kΩConnectionDIN plug (DIN 19262), waterproof, and 4 mm banana plugCable1 m fixed cableScope of delivery1 WTW SenTix 81 pH electrode with wetting capDropper bottle for refilling (included according to the WTW instructions)1 m fixed cable with DIN and banana plugs, permanently attached to the electrodeAccessories and procurement serviceReference electrolyte KCl 3 mol/l for refilling and buffer solutions for calibration are also available. If you require a different version or multiple electrodes, please enquire via the procurement service.
WTW SenTix 61 glass pH electrode, refillable, DIN connector, 103640
WTW lists a wide range of applications for these glass electrodes: from diluted acids and emulsions through to beer, milk and fruit juice, right up to serum and urine. The WTW SenTix 61 features a glass shaft, a refillable liquid electrolyte and a platinum wire junction. It measures from 0 to 14 pH at sample temperatures of 0 to 100 °C. If there is no built-in sensor, the temperature is entered on the measuring instrument or measured using an external sensor.Platinum wire junction and conical membraneThe glass shaft is 120 mm long and has a diameter of 12 mm. According to WTW, the platinum wire junction ensures optimum electrolyte flow without blockages. The membrane is conical in shape; according to WTW, it is impact-resistant and easy to clean. The membrane resistance at 25 °C is less than 600 MΩ. The reference system is 3 mol/l KCl, Ag+-free and refillable. According to WTW, the liquid electrolyte enables fast response times.Typical applications, according to WTWDiluted acids, salt solutions, emulsions and suspensionsCooling water, dye solutions and electroplating bathsDrinking water, groundwater, swimming pool water, lake water, surface water and seawaterSoil, paper and coffee extractsBeer, lemonade, fruit juice, vegetable juice, wine, mineral water, milk and vinegarHair dye, mouthwash and household cleanersEnzyme solutions, gastric juice, infusion solutions, protein-containing liquids, serum, Tris buffer solutions and urine (pharmaceuticals, biology, medicine)ConnectionThe SenTix 61 has a permanently attached 1 m cable with a waterproof DIN plug (DIN 19262). The variants in this series differ only in terms of plug, cable and temperature sensor; the electrode itself is identical. The choice therefore depends on the input of the measuring instrument. If a longer shaft is needed, the SenTix 91 has a length of 170 mm instead of 120 mm.Refilling and storageThe refill opening remains open during calibration and measurement. A dropper bottle is included, according to the WTW instructions. For short measurement breaks, the electrode is immersed in reference electrolyte (KCl 3 mol/l, Ag+-free) with the refill opening open. Overnight and for longer periods, it stays in the wetting cap, filled with reference electrolyte, with the refill opening closed. According to WTW, storing the electrode in a dry state or in deionised water can cause permanent damage. If the cap has dried out, the electrode needs at least 24 hours in reference electrolyte. As with any pH electrode, strong acids and alkalis, hydrofluoric acid, organic solvents, oils, fats and proteins shorten its service life.Technical detailsTypepH electrode, analogue, liquid electrolyteShaft materialGlassShaft length / shaft diameter120 mm / 12 mmElectrolyteKCl 3 mol/l, Ag+-free, refillableJunctionPlatinum wireMembrane shapeConicalpH measuring range0 to 14Temperature range0 to 100 °CMembrane resistance< 600 MΩ at 25 °CTemperature sensorNoneConnectionDIN plug (DIN 19262), waterproofCable1 m fixed cableScope of delivery1 WTW SenTix 61 pH electrode with wetting capDropper bottle for refilling (included according to the WTW instructions)1 m fixed cable with DIN plug, permanently attached to the electrodeAccessories and procurement serviceReference electrolyte KCl 3 mol/l for refilling and buffer solutions for calibration are also available. If you require a different version or multiple electrodes, please enquire via the procurement service.
WTW ProfiLine pH 3110 handheld pH meter, IP67, 2AA110
Whether in the laboratory or out by the water’s edge, a pH meter designed for mobile use must operate reliably even under harsh conditions. The WTW ProfiLine pH 3110 is a robust pocket-sized meter with IP 67 protection, battery operation and a 6-button control panel that can be operated even whilst wearing gloves.IP67 protection rating for field and laboratory useThe housing is IP 67-rated, dust-tight and temporarily waterproof. This means the meter can withstand splash water at the sampling point as well as use in damp laboratory environments. Protection class III also ensures safe low voltage during battery operation.Calibration with AutoCal TEC and AutoRead1-, 2- or 3-point calibration with freely selectable calibration points is available. The AutoCal TEC automatic buffer recognition function independently identifies technical buffers or DIN buffers, whilst the AutoRead function checks the stability of the measured value before it is accepted. An integrated calibration timer reminds the user when the next calibration is due.Measuring ranges and accuracyThe pH measurement range extends from -2.000 to +19.999 pH, with an accuracy of ± 0.1 to ± 0.005 pH depending on the selected resolution (± 1 digit in each case, at a sample temperature of 15 to 35 °C). In addition, the instrument measures mV in the range from -2,000 to +2,000 mV, as well as temperature from -5.0 to +105.0 °C with an accuracy of ± 0.1 K.Operation, memory and battery operationThe device is operated via 6 buttons, which can be used even whilst wearing gloves, and, according to the manufacturer, features a large, clear LCD display. The device stores up to 5,000 GLP entries internally. It is powered by four AA alkaline-manganese batteries, or alternatively by four NiMH rechargeable batteries (without an in-unit charging function), with a runtime of approximately 2,500 operating hours.Typical applicationsMobile pH measurement at water bodies and sampling pointsRoutine measurements in industrial and wastewater laboratoriesField measurements at varying locations thanks to battery operation and IP67 ratingCompact secondary unit alongside fixed measuring stations in the laboratoryA typical scenario is a sampling round at several measurement points: the device remains within easy reach in its case, measures pH and temperature directly on site and stores each measurement value with GLP reference, without the need to carry a mains socket or a laptop.Selecting the right electrodeThe ProfiLine pH 3110 has a DIN connector (coaxial plug according to DIN 19262) for the pH electrode and is supplied as a standalone unit without an electrode. It is compatible with WTW electrodes featuring a DIN connector, such as the SenTix 41 (item no. 103635) or the SenTix 81 precision glass electrode (item no. 103642). If you would like the unit and electrode as a complete set, we offer the ProfiLine pH 3110 Set 2 (item no. 2AA112), which includes the SenTix 41.Technical detailsTypePortable pH/mV meterpH measurement range-2.000…+19.999 pH (depending on range)pH accuracy± 0.1 / ± 0.01 / ± 0.005 pH depending on range, ± 1 digit, at 15…35 °CmV measurement range-1,200.0…+1,200.0 mV / -2,000…+2,000 mVmV accuracy± 0.3 mV / ± 1 mV, ± 1 digitTemperature measurement range-5.0…+105.0 °CTemperature accuracy± 0.1 K, ± 1 digitCalibration1-, 2- or 3-point calibration, AutoCal TEC, AutoRead, calibration timerDegree of protectionIP 67, protection class IIIPower supply4 × 1.5 V AA alkaline-manganese batteries (alternatively 4 × 1.2 V NiMH rechargeable batteries)Operating timeapprox. 2,500 operating hoursData storage5,000 GLP entriesDimensionsapprox. 180 × 80 × 55 mmWeightapprox. 0.4 kgOperating temperature / Storage temperature-10…+55 °C / -25…+65 °CConnectionDIN connector for pH electrode (coaxial plug according to DIN 19262)StandardsCE, IP 67 according to EN 60529, EMC according to EN 61326-1/EN 61000-3-2/EN 61000-3-3/FCC Class A, equipment safety according to EN 61010-1Scope of delivery1 WTW ProfiLine pH 3110 handheld meter in a caseSTP 4 and STP 7 buffer solutions3 mol/l KCl electrolyte top-up solutionQuick start guideBatteriesA pH electrode is not included in the scope of delivery; it must be ordered separately for measurement purposes.Regulatory informationThe ProfiLine pH 3110 is covered by WEEE registration number DE 29884659 held by Xylem Analytics Germany GmbH, a collective registration with the EAR Foundation for the WTW brand.Individual requirements and procurement serviceThe SenTix 41 (item no. 103635) and SenTix 81 (item no. 103642), as well as the technical buffer solutions pH 4.01 (item no. 108706) and pH 7.00 (item no. 108708) are suitable for measurement operation. If you require further accessories or have any questions regarding the appropriate combination, our procurement service will be happy to assist.
WTW digital IDS pH electrode SenTix 940, plastic shaft, 1.5 m fixed cable, 103740
With a digital IDS electrode, the calibration data is stored in the sensor, not in the measuring instrument. According to the WTW instructions, the electronics in the head store the sensor type, serial number and the last 10 calibrations. As a result, the correct slope and asymmetry automatically apply on the connected measuring instrument, and several calibrated sensors can be swapped on one instrument without recalibration. The WTW SenTix 940 has a gel electrolyte and a plastic shaft.Gel without refillingThe shaft is made of PPE/PS, is 120 mm long and has a diameter of 12 mm. The gel electrolyte is not refilled, and the electrode is low-maintenance. According to WTW, the fibre junction prevents blockages. The membrane is cylindrical, and according to the product page its resistance is below 1 GΩ. It measures from 0 to 14 pH at sample temperatures of 0 to 80 °C.Temperature recorded at the same timeAn NTC temperature sensor (30 kΩ) is built in, so a second sensor in the sample vessel is not needed. According to WTW, the IDS measuring electronics work with an accuracy of pH ±0.004, ±0.2 mV, ±0.1 °C (±1 digit in each case).Typical applications according to WTWSwimming pool waterWastewater in general, industrial wastewater and electroplating wastewaterGroundwaterLake water, surface water and seawaterConnection to the measuring instrumentThe SenTix 940 has a permanently attached cable of 1.5 m. The IDS plug is a 4-pin, waterproof plug connection with locking. The versions 940, 940-3 and 940-P have the same electrode and differ only in the connection. Which one is suitable depends on the distance between the sample and the measuring instrument.StorageBefore the first measurement, the wetting cap is removed, and gas bubbles behind the membrane are removed by shaking. During short breaks, the electrode is immersed in reference electrolyte (KCl 3 mol/l, Ag+-free); overnight and for longer, it stays in the wetting cap filled with it. If stored dry or in deionised water, it can be permanently damaged according to WTW. If the liquid in the cap has dried out, the electrode needs at least 24 hours in reference electrolyte. Strong acids and alkalis, hydrofluoric acid, organic solvents, oils, fats and proteins shorten the service life, as with any pH electrode.Technical detailsTypepH electrode, digital (IDS), gel electrolyteShaft materialPlastic (PPE/PS)Shaft length / shaft diameter120 mm / 12 mmElectrolyteGel, not refillableJunctionFibreMembrane shapecylindricalpH measuring range0 to 14Temperature range0 to 80 °CMembrane resistance< 1 GΩTemperature sensorNTC 30 kΩ, built inAccuracy of IDS electronicspH ±0.004, ±0.2 mV, ±0.1 °C (±1 digit in each case)ConnectionIDS plug, 4-pin, waterproof and lockableCable1.5 m fixed cableScope of delivery1 WTW SenTix 940 pH electrode with wetting capOperating instructionsFixed cable 1.5 m with IDS plug, permanently attached to the electrodeRegulatory informationAs an electrical device, the digital IDS electrode falls under the ElektroG. The manufacturer Xylem Analytics Germany GmbH (WTW brand) is registered under the WEEE registration number DE 29884659. How to return old appliances is described on the page Environment and disposal.Accessories and procurement serviceAlso available are reference electrolyte KCl 3 mol/l for the wetting cap and buffer solutions for calibration. For other IDS electrodes or larger quantities, there is the procurement service.
WTW ProfiLine pH 3110 Set 2 pH Measurement Kit with SenTix 41, 2AA112
If you don’t want to put together a pH meter and a suitable electrode separately, the WTW ProfiLine pH 3110 Set 2 offers a complete, ready-to-use package in a carrying case. As well as the 2AA110 meter, the set includes the SenTix 41 electrode, along with buffer solution, a stand and a beaker for your first measurements.What’s in the caseThe carrying case contains the ProfiLine pH 3110 meter, the SenTix 41 pH electrode (item no. 103635), STP 4 and STP 7 buffer solutions, a stand, a beaker, the quick start guide and the batteries. This means you can calibrate and take measurements immediately after unpacking, without having to order the electrode, buffers or accessories separately.Measuring instrument with IP67 rating and flexible calibrationThe main unit is technically equivalent to the 2AA110 single-unit model: IP 67 protection rating, 1- to 3-point calibration with AutoCal TEC and AutoRead stability check, integrated calibration timer and 6-button operation, even when wearing gloves. The pH measurement range extends from -2.000 to +19.999 pH, with additional mV and temperature measurement. The unit is powered by 4 AA batteries with a runtime of approx. 2,500 operating hours; it stores up to 5,000 GLP entries internally.SenTix 41 electrode included in the setThe included SenTix 41 has a plastic shaft with a low-maintenance gel electrolyte, a fibre diaphragm and an integrated NTC temperature sensor. It is connected via a 1 m fixed cable with a DIN plug and a 4 mm banana plug, compatible with the meter’s DIN input. The measurement range covers 0 to 14 pH at temperatures between 0 and 80 °C; the membrane resistance is less than 1 GOhm.Typical applicationsImmediate access to pH measurement without the need to purchase separate equipmentMobile use at water bodies and sampling points thanks to the carrying caseEquipping new measuring stations in the laboratory with a full range of accessoriesRoutine measurement in industrial and wastewater laboratoriesAn obvious example is the set-up of a new measurement station: rather than having to assemble the meter, electrode, buffer solution and accessories individually, Set 2 provides a calibration-ready workstation straight out of the case.Difference compared to the 2AA110 single unitThe ProfiLine pH 3110 single unit (item no. 2AA110) is supplied without an electrode and is aimed at customers who already own a suitable SenTix electrode or wish to use another model, such as the SenTix 81 precision electrode (item no. 103642). Set 2 eliminates this intermediate step and provides the meter, electrode, buffer solution and accessories as a complete package.Accessories for immediate useThe stand and beaker included in the case allow for a stable measurement setup directly at the workstation, without the need to organise additional laboratory equipment. The included STP 4 and STP 7 buffer solutions already cover one acidic and one neutral calibration point; for a complete 3-point calibration, an alkaline buffer solution (pH 10) can be added if required.The carrying case protects the measuring instrument, electrode and accessories during transport between sampling points or laboratory workstations and keeps the individual parts organised in one place, rather than having to gather them together separately.Technical detailsTypePortable pH/mV meter with pH electrode included in the setpH measurement range (meter)-2.000…+19.999 pH (depending on range)Degree of protectionIP 67, protection class IIICalibration1-, 2- or 3-point calibration, AutoCal TEC, AutoRead, calibration timerPower supply4 × 1.5 V AA alkaline-manganese batteries (alternatively 4 × 1.2 V NiMH rechargeable batteries)Operating timeapprox. 2,500 operating hoursData storage5,000 GLP entriesDimensions / Weight of unitapprox. 180 × 80 × 55 mm / approx. 0.4 kgElectrode included in the setSenTix 41 (Item No. 103635)Electrolyte for electrodeGel, non-refillableTemperature sensor electrodeNTC 30 kOhm, integratedMeasuring range of pH / temperature electrode0…14 pH, 0…80 °CElectrode connection1 m fixed cable, DIN plug and 4 mm banana plugsStandardsCE, IP 67 according to EN 60529, EN 61010-1 (instrument); CE Declaration of Conformity SenTix/TA-Sensolyt, DIN 19262 (electrode)Scope of delivery1 WTW ProfiLine pH 3110 handheld meter in a carrying case1 SenTix 41 pH electrode (item no. 103635)Buffer solutions STP 4 and STP 7Stand and beakerQuick start guideBatteriesRegulatory informationThe WEEE registration number DE 29884659 held by Xylem Analytics Germany GmbH applies to the instrument component; this is a collective registration with the EAR Foundation for the WTW brand. The SenTix-41 electrode included in the set is a passive sensor without its own electronics and is therefore not affected by this registration.Individual requirements & procurement serviceOnce the buffer solution in the set has been used up, we offer refills of the Technical Buffer Solution pH 4.01 (item no. 108706) and pH 7.00 (item no. 108708). For replacement electrodes, additional accessories or specific enquiries regarding the kit, our procurement service provides support.
WTW Standard (DIN/NIST) buffer solution PL 7, pH 6.865/6.87, PTB/NIST-traceable calibration solution according to DIN 19266-01:2000, ± 0.02 pH, 250 ml, 109120
An electrode that is incorrectly calibrated in the neutral range will introduce a bias into every subsequent measurement, particularly where pH 7, as the zero point of the scale, plays a key role. The WTW Standard (DIN/NIST) buffer solution PL 7 provides a traceable reference for this purpose: a working reference buffer solution according to DIN 19266-01:2000, certified as traceable to PTB/NIST, with an accuracy of ± 0.02 pH at 25 °C. Together with PL 4 and PL 9, it forms the midpoint of a complete, documentable three-point calibration. Standard (DIN/NIST) buffer solution PL 7: higher accuracy class than the technical range The key difference from the ‘technical’ WTW buffer solution range lies in the accuracy class and traceability. The WTW technical buffer solution pH 7 is designed for daily routine calibration and reliably covers everyday laboratory work. The Standard (DIN/NIST) buffer solution PL 7 goes one step further: As a working reference buffer solution according to DIN 19266-01:2000, it is certified as PTB/NIST-traceable and specified to ± 0.02 pH at 25 °C. This makes it a suitable choice wherever the calibration itself must be documented and traceable, such as in ISO/IEC 17025-accredited testing laboratories, in pharmaceutical analysis or in metrologically demanding research. Buffer system comprising two phosphate salts PL 7 is based on a mixture of disodium hydrogen phosphate and potassium dihydrogen phosphate as a buffer system and achieves a pH value of 6.87 at 20 °C, stated on the label as pH 6.865 according to DIN or pH 6.87 according to NIST. The density is 1.01 g/cm³, the melting point is -0.3 °C and the boiling point is 100 °C. Under the CLP Regulation, the solution is not classified as a hazardous substance and is not a dangerous good, which simplifies storage, transport and handling in day-to-day laboratory work. Each bottle bears its own batch code with an expiry date, ensuring that the batch used can always be linked to the corresponding test certificate and remains clearly traceable within the documentation of a quality management system. Traceability as part of quality assurance Traceability means that the printed pH value can be traced back through an unbroken chain of reference measurements to the national metrology institutes PTB and NIST. For a testing laboratory accredited to ISO/IEC 17025, this is precisely the difference between a plausible and a robust measurement: not only the electrode itself, but also the reference used to calibrate it, must be documented and traceable. The zero point at pH 7, in particular, affects the entire calibration curve, which is why a traceable, certified buffer is especially important at this point. With PL 7, this requirement can be met directly via the batch identification and the associated test certificate, without the need for additional in-house verifications in the laboratory. Storage and handling Storage in the tightly sealed original container at 15 to 25 °C is recommended. According to TRGS 510, the solution is classified in storage class LGK 12 (non-flammable liquids) and is not considered to pose a risk to water. As PL 7 is neither classified as a hazardous substance nor declared as dangerous goods, no special protective measures are required when opening or dispensing it. Nevertheless, safety goggles with side protection are recommended for the safe handling of the reference solution, and the container should be resealed promptly after use to prevent the reference value from shifting due to evaporation or the absorption of CO2 from the air. Typical applications PL 7 is used wherever the calibration of a pH electrode must not only be ‘adequate’ but also verifiable through documentation: Two- or three-point calibration of pH electrodes in the neutral measuring range, in conjunction with the WTW buffer solutions PL 4 and PL 9 Zero-point adjustment of the pH scale as the central reference point for every calibration routine Traceable calibration in accredited testing laboratories according to ISO/IEC 17025 Quality control in pharmaceutical and active ingredient analysis Calibration prior to the analysis of approximately neutral samples, such as drinking water or cell culture media Research institutions with stringent requirements regarding measurement uncertainty Buffer solutions according to DIN 19266-01:2000 are among the most widely used working reference buffer solutions, as their composition is specified directly in the standard. When PL 7 is used in conjunction with PL 4 and PL 9 for a three-point calibration, this trio covers the entire pH range relevant to practical applications, from acidic through neutral to alkaline, with the same accuracy class and the same traceability to PTB/NIST. This simplifies documentation, as all three calibration points can be included in the same test certificate format. Technical details Trade namePL 7 Buffer systemDisodium hydrogen phosphate, potassium dihydrogen phosphate pH value at 20 °C6.87 (labelling: pH 6.865 according to DIN / pH 6.87 according to NIST) Accuracy± 0.02 pH at 25 °C TraceabilityPTB/NIST StandardDIN 19266-01:2000 Density at 20 °C1.01 g/cm³ Melting point/freezing point-0.3 °C Boiling point100 °C Physical state / Colour / OdourLiquid, colourless, odourless Hazard classification (CLP)Not classified Dangerous goodsNo Storage class (TRGS 510)Class 12 (non-flammable liquids) Recommended storage temperature15-25 °C Container size250 ml Scope of delivery 1 bottle of WTW Standard (DIN/NIST) buffer solution PL 7, 250 ml, with batch number and expiry date Individual requirements and procurement service For a complete three-point calibration, we also offer the WTW Standard (DIN/NIST) buffer solutions PL 4 (pH 4.006/4.01) and PL 9 (pH 9.180/9.18). If you carry out daily routine calibration using the technical accuracy class, you will find the WTW technical buffer solution pH 7 with the same pH value in our range. You can find suitable pH electrodes for calibration in our range of electrodes. Our procurement service is on hand to assist you with additional accessories for your pH measurement technology or with individual procurement enquiries.
Content: 250 ml (€11.60 / 100 ml)
WTW SenTix 21 pH Electrode, Plastic Shaft, Gel Electrolyte, DIN Connector, 103631
Measuring pH in wastewater, aquariums or swimming pools should not depend on a refilling routine. The WTW SenTix 21 features a plastic shaft and a gel electrolyte which, according to WTW, is not refilled. The electrode is low-maintenance. The pH measuring range extends from 0 to 14, and it can be used at sample temperatures of 0 to 80 °C.Gel electrolyte and fibre junctionThe shaft is made of PPE/PS, is 120 mm long and has a diameter of 12 mm. The membrane is cylindrical; its resistance at 25 °C is less than 1 GΩ. According to WTW, the fibre junction prevents blockages. There is no need to monitor or top up the electrolyte level. If the electrolyte is meant to be refillable, the SenTix 51 and 52 with liquid electrolyte and a ceramic junction in a plastic shaft are the alternative.Connection and temperature measurementThe SenTix 21 has a permanently attached 1 m cable with a waterproof DIN plug (DIN 19262). If there is no built-in sensor, the temperature is entered on the measuring instrument or measured using an external sensor. The gel electrodes in this range differ in plug, cable length and temperature sensor. You should therefore establish which input the measuring instrument has before placing your order.Typical applications according to WTWWhen taking samples from water bodies, at the edge of a pool or from a wastewater pipe, what counts is an electrode that is quickly ready for use. WTW names the following media for this series:Electroplating effluent, industrial wastewater and wastewater in generalAquarium and swimming pool waterGroundwater, lake water, surface water and seawaterHousehold cleanersStorage and careBefore the first measurement, remove the wetting cap; gas bubbles behind the membrane can be removed by shaking. For short measurement breaks, immerse the electrode in reference electrolyte (3 mol/l KCl, Ag+-free). Overnight and for longer periods, it stays in the wetting cap, filled with the same electrolyte. According to WTW, storing the electrode dry or in deionised water can cause permanent damage. If the cap has dried out, the electrode needs at least 24 hours in reference electrolyte. As with any pH electrode, strong acids and alkalis, hydrofluoric acid, organic solvents, oils, fats and proteins shorten its service life.Technical detailsTypepH electrode, analogue, gel electrolyteShaft materialPlastic (PPE/PS)Shaft length / Shaft diameter120 mm / 12 mmElectrolyteGel, non-refillableReference systemSilver/silver chlorideJunctionFibreMembrane shapeCylindricalpH measuring range0 to 14Temperature range0 to 80 °CMembrane resistance< 1 GΩ at 25 °CTemperature sensorNoneConnectionDIN plug (DIN 19262), waterproofCable1 m fixed cableScope of delivery1 WTW SenTix 21 pH electrode with wetting cap1 m fixed cable with DIN plug, permanently attached to the electrodeAccessories and procurement serviceReference electrolyte KCl 3 mol/l for the wetting cap and buffer solutions for calibration are also available. Enquiries regarding other SenTix models or larger quantities go through our procurement service.
WTW Technical Buffer Solution TPL 7, pH 7.00, 250 ml, 108802
Before a pH electrode can provide reliable readings, it must be calibrated, and this requires a stable technical buffer solution with a pH of 7. The WTW technical buffer solution pH 7.00 provides the neutral reference point for 2- or 3-point calibration, as routinely carried out in laboratories in the pharmaceutical, industrial, research and water analysis sectors. It is available in three container sizes ranging from 50 ml to 1,000 ml, depending on how frequently calibration is carried out and how many electrodes are in use. Why calibrate regularly The glass membrane of a pH electrode changes over time; ageing, deposits or temperature fluctuations cause the slope of the calibration curve to shift. Without regular calibration against a known buffer solution, measured values gradually drift without this being immediately apparent. A fresh technical buffer solution with a defined pH value and documented accuracy is therefore essential for reliable measurement results, regardless of the pH meter or electrode type used. Phosphate buffer with documented accuracy The technical buffer solution pH 7 is based on a phosphate buffer comprising disodium hydrogen phosphate and potassium dihydrogen phosphate. At 20 °C, the pH value is exactly 7.00, with an accuracy of ± 0.03 pH. This tight tolerance ensures reproducible calibration, regardless of the electrode or measuring instrument used. Particularly when several measuring points or sites require the same reference, documented, consistent accuracy forms the basis for comparable results. The neutral reference point for 2- or 3-point calibration In practice, pH 7 is usually the first point in a 2- or 3-point calibration, typically supplemented by pH 4 and pH 10. If you have all three buffer levels in stock, you will fully cover the measurement range relevant to most applications. A simple 1-point calibration at pH 7 only indicates whether the electrode’s zero point is correct, but says nothing about the slope of the calibration curve outside the neutral range. For measurements that must also be reliable in the acidic or alkaline ranges, at least a second calibration point is therefore advisable. We also offer the same technical buffer solution with pH 4.01 and, in trace quality, with pH 10.01. WTW, a brand of Xylem The buffer solution is supplied by WTW, an established brand in pH measurement technology and electrochemistry, which is now part of Xylem. Many laboratories already rely on WTW measuring instruments and electrodes; this technical buffer solution is suitable for them as a matched calibration solution. In principle, however, the buffer solution can be used with any pH electrode and any pH meter, regardless of the manufacturer; calibration is not tied to a specific measuring instrument. Pack sizes for the technical buffer solution pH 7 Select the appropriate pack size above: STP 7 as a 50 ml bottle for economical use or as a supplement in an electrode case, TPL 7 with 250 ml for routine laboratory work, and TEP 7 with 1,000 ml for frequent calibration requirements or multiple measuring points. ModelVolume STP 750 ml TPL 7250 ml TEP 71,000 ml Storage, shelf life and handling At 20 °C, the buffer solution has a density of 1.01 g/cm³ and a melting point of -0.3 °C. Unopened, it has a shelf life of 3 years when stored at 15 to 25 °C. It is not classified under GHS/CLP and is not a dangerous good, which significantly simplifies storage, handling and dispatch in day-to-day laboratory work; there are no special dangerous goods requirements or labelling regulations to observe. Avoid contamination To ensure that the calibration remains reliable throughout the entire shelf life, buffer solution that has been removed should not be poured back into the bottle. Even minor contaminants from the measurement environment or the electrode can alter the pH value of the remaining solution and distort subsequent calibrations. For daily use, it is therefore advisable to use a small calibration vessel into which only as much buffer solution is poured as is required for the current calibration. The bottle itself should be kept tightly sealed and stored at a temperature between 15 and 25 °C to ensure that the documented accuracy of ± 0.03 pH is maintained until the end of the three-year shelf life. Typical applications The technical buffer solution pH 7 is used wherever pH electrodes need to be calibrated regularly: Routine calibration of pH electrodes in pharmaceutical quality assurance Water analysis, for example in drinking water and process water monitoring Process control in industry, wherever pH values in the neutral range are monitored Research and teaching, as a reliable reference point for measurement series Commissioning and functional testing of new pH electrodes prior to first use Technical details Buffer systemDisodium hydrogen phosphate, potassium dihydrogen phosphate (phosphate buffer) pH value at 20 °C7.00 Accuracy± 0.03 pH Density at 20 °C1.01 g/cm³ Melting point-0.3 °C Shelf life when unopened3 years Storage temperature15 to 25 °C GHS/CLP classificationNot classified, not a dangerous good Scope of delivery 1 bottle of WTW technical buffer solution pH 7.00 in the selected container size (50 ml, 250 ml or 1,000 ml) Individual requirements and procurement service For complete 3-point calibration, we also offer the same technical buffer solution with pH 4.01 and, in trace quality, with pH 10.01, as well as suitable pH electrodes. If you have larger requirements, need custom container sizes or have any questions about the appropriate calibration solution, our procurement service will be happy to assist you.
Content: 250 ml (€6.84 / 100 ml)
WTW Technical Buffer Solution TPL 4, 1 bottle of 250 ml: pH 4.01, #108800
At the acidic end of the pH scale, the technical buffer solution pH 4 provides the second fixed reference point for the calibration of pH electrodes. The WTW technical buffer solution pH 4.01 is used in conjunction with pH 7 and pH 10 for 2- or 3-point calibration, thereby covering the acidic measurement range, which plays a key role in many applications in industry, water analysis and research. It is available in three container sizes ranging from 50 ml to 1,000 ml, so that it can meet both occasional requirements in small laboratories and regular consumption where frequent calibration is required. Potassium hydrogen phthalate as the buffer substance Potassium hydrogen phthalate is used as the buffer system; it is one of the most common substances for acidic reference buffer solutions. At 20 °C, the pH value is 4.01, with an accuracy of ± 0.03 pH. This tolerance is narrow enough to achieve comparable, reproducible calibration results even when using multiple electrodes and measuring instruments in the laboratory, regardless of which team member carries out the calibration. Why an acidic calibration point is important Calibration in the neutral range alone says little about how precisely an electrode measures outside pH 7. If the actual sample deviates significantly from the neutral range, as is often the case with acidic process solutions, foodstuffs or environmental samples, a second calibration point at pH 4 ensures that the slope of the electrode is correctly recorded over a wider range. Combined with pH 7 and pH 10, this results in a complete 3-point calibration that delivers reliable measurement results even when sample values fluctuate significantly. WTW, a brand of Xylem The buffer solution is supplied by WTW, an established brand in pH measurement technology and electrochemistry, which is now part of Xylem. Many laboratories already rely on WTW measuring instruments and electrodes; the technical buffer solution is designed to complement these as a matched calibration solution. However, it can generally be used with any pH electrode and any pH meter, regardless of the manufacturer; the calibration is not tied to a specific measuring instrument. Pack sizes of the technical buffer solution pH 4 Select the appropriate pack size above: STP 4 as a 50-ml bottle for economical use or as a supplement in an electrode case; TPL 4 with 250 ml for routine laboratory use; and TEP 4 with 1,000 ml for frequent calibration requirements or multiple measuring points. ModelVolume STP 450 ml TPL 4250 ml TEP 41,000 ml Storage, shelf life and handling At 20 °C, the buffer solution has a density of 1.01 g/cm³ and a melting point of -1.6 °C. Unopened, it has a shelf life of 3 years when stored at 15 to 25 °C. It is not classified under GHS/CLP and is not a dangerous good, which simplifies storage, handling and dispatch in everyday laboratory work without the need for additional dangerous goods labelling. Avoiding contamination To ensure that calibration remains reliable throughout the entire shelf life, buffer solution that has been removed should not be poured back into the bottle. Even small amounts of contamination from the measurement environment or from the electrode can alter the pH value of the remaining solution and distort subsequent calibrations; the phthalate buffer is particularly sensitive to foreign ions in the acidic range. For daily use, it is therefore advisable to use a small calibration vessel into which only as much buffer solution is poured as is required for the current calibration. The bottle itself should be kept tightly sealed and stored at a temperature between 15 and 25 °C to ensure that the documented accuracy of ± 0.03 pH is maintained until the end of the three-year shelf life. Typical applications The technical buffer solution pH 4 is used wherever pH electrodes need to measure reliably in the acidic range, not only for a one-off calibration but as an integral part of ongoing quality assurance: Acidic calibration point in industrial process control, e.g. for cleaning and process solutions Water analysis and environmental samples with low pH values Food- and beverage-related laboratory applications involving acidic samples Research and teaching, as a second reference point alongside pH 7 and pH 10 Commissioning and functional testing of new pH electrodes prior to first use Technical details Buffer systemPotassium hydrogen phthalate pH value at 20 °C4.01 Accuracy± 0.03 pH Density at 20 °C1.01 g/cm³ Melting point-1.6 °C Shelf life when unopened3 years Storage temperature15 to 25 °C GHS/CLP classificationNot classified, not a dangerous good Scope of delivery 1 bottle of WTW technical buffer solution pH 4.01 in the selected container size (50 ml, 250 ml or 1,000 ml) Individual requirements & procurement service For complete 3-point calibration, we also offer the same technical buffer solution with pH 7.00 and, in trace quality, with pH 10.01, as well as suitable pH electrodes. For larger quantities, custom container sizes or enquiries regarding the appropriate calibration solution, our procurement service will be happy to assist you.
Content: 250 ml (€6.80 / 100 ml)
WTW ProfiLine pH 3310 handheld meter (pH/mV, DIN connector), 2AA310
The WTW ProfiLine pH 3310 is the professional standard handheld meter for all users who demand high standards of reliability, data security and robustness, whether in the field, in the laboratory or in process monitoring. It combines precise digital analysis with a connection for tried-and-tested analogue pH electrodes (DIN). Robust field-ready design (IP 67) The instrument is fully waterproof and dustproof to IP 67. For specialist buyers working in the field (environmental measurement technology, aquaculture) or in harsh production environments, the instrument is protected even in the rain or if dropped into water. The backlit graphic display is clearly legible even in poor lighting conditions. Measurement reliability thanks to the CMC function A key advantage of the 3310 series is ‘Continuous Measurement Control’ (CMC). The device continuously displays a graphical indication to the user showing whether the current measurement is still within the range of the last calibration. This provides immediate assurance of the reliability of the measured value and prevents measurement errors caused by out-of-date calibrations. Data logger for GLP/AQS documentation The pH 3310 is suitable for quality assurance (AQS). It features a large data logger capable of storing up to 5,000 automatic (time-controlled) or 500 manual (at the touch of a button) data records. All data can be transferred to a PC via the integrated mini-USB interface including timestamps and sensor ID, which supports documentation in a GLP environment. Flexible electrode connection (DIN) This meter is deliberately equipped with a standard DIN connector (for pH/mV) and 4 mm banana sockets (for separate temperature sensors). This allows specialist buyers to continue using existing standard analogue electrodes from various manufacturers flexibly. Technical details Measurement channels: 1 (pH/mV) pH range: -2.000 to +19.999 pH mV range: ±1,200.0 mV; ±2,500 mV Temperature range: -5.0 to +105.0 °C Connection (pH): DIN (for pH electrodes) Connection (temperature): 2 × 4 mm banana sockets (for TFK probes or similar) Data storage: 500 (manual), 5,000 (automatic) Interface: Mini-USB-B (waterproof) Degree of protection: IP 67 Display: LCD (backlit, graphical) Calibration (pH): 1-, 2-, 3-, 4-, 5-point (WTW TEC / DIN buffers) Functions: CMC (Continuous Measurement Control) Power supply: 4 x 1.5 V AA (batteries) or USB operation Scope of delivery ProfiLine pH 3310 meter (main unit) 4 x AA batteries Quick start guide CD-ROM (with USB drivers and software) USB cable (A to Mini-B) Important note: The case, pH electrodes and temperature probe (TFK) are accessories and are not included with the basic unit (2AA310). Individual requirements & procurement service Do you need advice on the right pH electrode for your application (e.g. a robust SenTix 41 with a DIN plug) or a separate temperature probe (TFK 325)? Our team of experts will be happy to put together a complete set for you. For accessories not listed here, please use our bespoke procurement service.
WTW ProfiLine pH 3310 Set 2 pocket pH meter (logger & USB), 2AA312
The WTW ProfiLine pH 3310 Set 2 is a professional, portable pH measurement system designed for precise measurements in the field and data documentation in the GLP/AQS environment. Unlike the basic 3110 model, the 3310 features an integrated data logger capable of storing up to 5,000 entries and a waterproof mini-USB interface. This enables the automated recording of measurement series (e.g. long-term monitoring of water bodies) and rapid transfer to a PC without the need for proprietary adapters. Measurement technology and process reliability The device offers 5-point calibration and the tried-and-tested CMC (Continuous Measurement Control) function. This displays on the backlit graphic display whether the current measured value is still within the calibrated range and issues a warning in the event of deviations. This increases the reliability of the measured values, particularly with changing sample matrices. Electrode and robustness ‘Set 2’ includes the low-maintenance SenTix® 41 pH electrode. It features a robust plastic shaft, an integrated temperature sensor (NTC 30 kOhm) for automatic temperature compensation, and a gel electrolyte that eliminates the need for refilling. The meter itself is waterproof to IP 67 (including the USB socket!) and can withstand brief submersion, making it suitable for harsh environments or sewage treatment works. Technical details pH measurement range: -2.000 … +19.999 pH Accuracy (pH): ±0.005 pH mV measurement range: ±1,200.0 / ±2,500 mV Temperature measurement range: -5.0 … +105.0 °C Calibration: 1- to 5-point (22 buffer sets stored) Data memory: 5,000 entries (automatic) / 200 (manual) Interface: Mini-USB-B (waterproof) Degree of protection: IP 67 Power supply: 4 x 1.5 V AA (up to 100 hours of continuous operation) or via USB Scope of delivery ProfiLine pH 3310 meter SenTix® 41 pH electrode (gel, integrated temperature sensor) STP 4 buffer solution (50 ml) STP 7 buffer solution (50 ml) Measuring beaker Stand Professional carrying case USB cable (A to Mini-B) CD-ROM with driver software Batteries (4x AA) Quick start guide Individual requirements and procurement service Do you require more precise glass electrodes (e.g. SenTix 81) for laboratory applications, or a kit for drinking water analysis or industrial requirements? We will gladly advise you on request.
WTW TFK 150 temperature probe for automatic temperature compensation, 1 m cable, 102274
The WTW TFK 150 is a temperature sensor for pH or redox electrodes that do not have their own sensor. It supplies the meter with the sample temperature for automatic temperature compensation.Temperature during calibration and measurementFor redox and ISE measurements, the probe is also used for compensation. Like the electrode, it is immersed in the sample and should be rinsed along with the electrode before each new sample.Cable and connectorThe sensor is fitted with a 1 m long fixed cable with a waterproof connector. We would be happy to check whether the temperature input on your meter is compatible with the TFK 150 before you place your order.Where the TFK 150 is usedThe probe is designed for automatic temperature compensation during pH, redox and ISE measurements. It also serves as an external probe for conductivity cells and the D 300/pH flow-through cell. The SenTix 60 pH electrode does not have its own temperature sensor, nor does the SenTix 22. The SenTix 42, for example, features a probe integrated directly into the shaft.Typical applicationsAutomatic temperature compensation for pH, redox and ISE measurementsExternal temperature probe for conductivity cells and the D 300/pH flow-through cellTechnical detailsTypeTemperature sensor (NTC) for automatic temperature compensationCable1 m fixed cable with waterproof connectorScope of delivery1 WTW TFK 150 temperature probe with 1 m cableIndividual requirements and procurement serviceA probe usually goes with a suitable electrode, and the correct combination depends on the meter. Our procurement service can help with selection and ordering.
WTW Standard (DIN/NIST) buffer solution PL 4, pH 4.006/4.01, PTB/NIST-traceable calibration solution according to DIN 19266-01:2000, ± 0.02 pH, 250 ml, 109110
Anyone calibrating a pH electrode in an accredited testing laboratory, in pharmaceutical quality control or in research cannot do without a fully traceable reference. The WTW Standard (DIN/NIST) buffer solution PL 4 delivers exactly that: a working reference buffer solution according to DIN 19266-01:2000, which is certified as traceable to both the PTB and NIST and achieves an accuracy of ± 0.02 pH at 25 °C. It thus covers the acidic range of the pH scale and, together with the WTW buffer solutions PL 7 and PL 9, forms the basis for a complete, documentable three-point calibration. Standard (DIN/NIST) buffer solution PL 4: higher accuracy class than the technical range The key difference from the ‘technical’ WTW buffer solution range lies in the accuracy class and traceability. Technical buffer solutions are designed for the daily routine calibration of pH electrodes and reliably cover everyday laboratory work. The Standard (DIN/NIST) buffer solution PL 4 goes one step further: As a working reference buffer solution according to DIN 19266-01:2000, it is certified as PTB/NIST-traceable and specified to ± 0.02 pH at 25 °C. This makes it a suitable choice wherever the calibration itself must be documented and traceable, for example in ISO/IEC 17025-accredited testing laboratories, in pharmaceutical analysis or in metrologically demanding research. Buffer system: potassium hydrogen phthalate PL 4 is based on potassium hydrogen phthalate as the buffer system and achieves a pH value of 4 at 20 °C, stated on the label as pH 4.006 according to DIN or pH 4.01 according to NIST. Its density is 1.01 g/cm³, its melting point is -1.6 °C and its boiling point is 100 °C. Under the CLP Regulation, the solution is not classified as a hazardous substance and is not a dangerous good, which simplifies storage, transport and handling in day-to-day laboratory work. Each bottle bears its own batch code with an expiry date, so that the batch used can be linked to the corresponding test certificate at any time and remains clearly traceable within the documentation of a quality management system. Traceability as part of quality assurance Traceability means that the printed pH value can be traced back through an unbroken chain of comparison measurements to the national metrology institutes PTB and NIST. For a testing laboratory accredited to ISO/IEC 17025, this is precisely the difference between a plausible and a robust measurement: not only the electrode itself, but also the reference against which it was calibrated, must be documented and traceable. With PL 4, this requirement can be met directly via the batch identification and the associated test certificate, without the need for additional in-house verifications in the laboratory. Storage and handling Storage in the tightly sealed original container at 15 to 25 °C is recommended. According to TRGS 510, the solution is classified in storage class LGK 12 (non-flammable liquids), is not classified as hazardous to water and, according to the safety data sheet, is considered readily biodegradable. As PL 4 is neither classified as a hazardous substance nor declared as dangerous goods, no special protective measures are required when opening or dispensing it. Nevertheless, for safe handling of the reference solution, safety goggles with side protection are recommended, and the container should be resealed promptly after use to prevent the reference value from shifting due to evaporation or the absorption of CO2 from the air. Typical applications PL 4 is used wherever the calibration of a pH electrode must not only be ‘adequate’ but also verifiable through documentation: Two- or three-point calibration of pH electrodes in the acidic measurement range, in conjunction with the WTW buffer solutions PL 7 and PL 9 Traceable calibration in accredited testing laboratories according to ISO/IEC 17025 Quality control in pharmaceutical and active ingredient analysis Calibration prior to the analysis of acidic samples, such as fruit juices, wine or soil extracts Research institutions with stringent requirements regarding measurement uncertainty For buffer solutions according to DIN 19266-01:2000, the composition is specified directly in the standard. When PL 4 is used in conjunction with PL 7 and PL 9 for a three-point calibration, this trio covers the entire pH range relevant to practical applications, from acidic through neutral to alkaline, with the same accuracy class and the same traceability to PTB/NIST. This simplifies documentation, as all three calibration points can be included in the same test certificate format. Technical details Trade namePL 4 Buffer systemPotassium hydrogen phthalate pH value at 20 °C4 (labelled: pH 4.006 according to DIN / pH 4.01 according to NIST) Accuracy± 0.02 pH at 25 °C TraceabilityPTB/NIST StandardDIN 19266-01:2000 Density at 20 °C1.01 g/cm³ Melting point/freezing point-1.6 °C Boiling point100 °C Physical state / Colour / OdourLiquid, colourless, odourless Hazard labelling (CLP)Not classified Dangerous goodsNo Storage class (TRGS 510)Class 12 (non-flammable liquids) Recommended storage temperature15-25 °C Container size250 ml Scope of delivery 1 bottle of WTW Standard (DIN/NIST) buffer solution PL 4, 250 ml, with batch number and expiry date Individual requirements and procurement service For a complete three-point calibration, we also offer the WTW Standard (DIN/NIST) buffer solutions PL 7 (pH 6.865/6.87) and PL 9 (pH 9.180/9.18). If you carry out daily routine calibration using the technical accuracy class, you will find the WTW Technical buffer solution TPL 4 with the same pH value in our range. You can find suitable pH electrodes for calibration in our range of electrodes. Our procurement service is on hand to assist you with additional accessories for your pH measurement technology or with individual procurement enquiries.
Content: 250 ml (€11.60 / 100 ml)
WTW inoLab pH 7110 DIN Laboratory pH Meter (basic unit), 1AA110
The WTW inoLab® pH 7110 (MPN 1AA110) is the precise entry-level instrument for routine laboratories that rely on traditional DIN connection technology. It offers the same high-quality measurement electronics as the ‘larger’ 7310 series (accuracy ±0.005 pH), but reduces complexity to the pure measurement task. This model is ideal for workstations where no extensive GLP documentation or data storage is required, but where the focus is on fast, reliable readings. DIN connector and compatibility Unlike the BNC version, this device is fitted with a DIN socket, which is widely used in German-speaking laboratories. This makes it the perfect replacement for existing WTW set-ups, as existing quality electrodes with DIN connectors (e.g. the SenTix series) can continue to be used seamlessly without the need for adaptors. Intuitive operation and AutoRead The large, segmented LCD display clearly shows the pH value and temperature at a glance. Operation is via a smooth, easy-to-clean membrane keypad, which also makes it easier to use whilst wearing gloves. The tried-and-tested “AutoRead” function ensures objective measurement results: it monitors the stability of the measurement signal and only releases the value once it has “stabilised”. This prevents reading errors caused by recording the value too early and significantly increases reproducibility. Calibration convenience The instrument supports 1- to 3-point calibration with automatic buffer recognition for WTW buffer sets as well as DIN/NIST buffers. An integrated calibration timer reminds the user at adjustable intervals when recalibration is required, to ensure long-term process reliability. Temperature measurement is carried out via separate 4 mm banana sockets. Technical details pH measurement range: -2.000 … +19.999 pH Accuracy (pH): ±0.005 pH mV measurement range: ±1200.0 / ±2,000 mV Accuracy (mV): ±0.3 mV Temperature measurement range: -5.0 … +105.0 °C Calibration: 1-, 2- or 3-point (WTW / DIN/NIST) pH connection: DIN socket (19262) Temperature connection: 2 × 4 mm banana sockets Display: LCD segment display (black and white) Power supply: Universal mains adaptor or 4 × 1.5 V AA batteries Degree of protection: IP 43 Scope of delivery inoLab® pH 7110 meter (DIN) Universal mains adaptor Stand (multi-purpose stand) Operating instructions Note: This offer (1AA110) does not include a pH electrode. This must be ordered separately or an existing electrode can be used. Individual requirements & procurement service Do you need suitable DIN electrodes (e.g. SenTix 41 or 81) or BNC-to-DIN adapter cables to use third-party sensors? We’ll put together a suitable accessory pack for you, including certified buffer solutions for your quality assurance.
WTW Technical Buffer Solution TEP 10 Trace, 1 bottle containing 1 L: pH 10.01, #108703
For the alkaline calibration point of a pH electrode, a technical buffer solution with a pH of 10 is required, which does not introduce any contamination into the sample, even in demanding applications such as trace analysis. The WTW technical buffer solution pH 10.01 Trace is the low-trace-metal version of the third calibration point, usually supplemented by pH 7 and pH 4, and thus covers 2- or 3-point calibration in the alkaline range. It is available in two container sizes, 250 ml and 1,000 ml, and is therefore suitable for both day-to-day laboratory use and applications requiring more frequent calibration. Trace-grade carbonate buffer The buffer system consists of a combination of sodium carbonate and sodium hydrogen carbonate, forming a carbonate buffer. The term ‘Trace’ denotes a formulation low in trace metals, which is particularly relevant where calibration solutions must not come into contact with sensitive analytical equipment or downstream trace metal measurements. The pH value at 25 °C is 10.01, with an accuracy of ± 0.03 pH. Reference temperature 25 °C Unlike the technical buffer solutions pH 4 and pH 7, which are specified at 20 °C, the pH value of the Trace buffer solution pH 10.01 is specified at 25 °C. The pH value of a buffer solution depends on the temperature, which is why the reference temperature is stated. To ensure correct calibration in the alkaline range, it is advisable to bring the temperature of the buffer solution as close as possible to this reference value before immersing the electrode. WTW, a brand of Xylem The buffer solution is supplied by WTW, an established brand in pH measurement technology and electrochemistry, which is now part of Xylem. Many laboratories already rely on WTW measuring instruments and electrodes; this technical buffer solution serves as a compatible calibration solution. However, it can generally be used with any pH electrode and any pH meter, regardless of the manufacturer; the calibration is not tied to a specific measuring instrument. The ‘Trace’ quality in particular is a feature that goes beyond the mere pH value and is aimed at laboratories that place particular emphasis on the purity of their calibration solutions. Pack sizes of the technical buffer solution pH 10.01 Trace Select the appropriate container size above: TPL 10 Trace (250 ml) for routine laboratory use, or TEP 10 Trace (1,000 ml) for frequent calibration requirements or multiple measuring points. A 50-ml container size is not available in the Trace grade. ModelVolume TPL 10 Trace250 ml TEP 10 Trace1,000 ml Storage, shelf life and handling At 20 °C, the buffer solution has a density of 1.01 g/cm³ and a melting point of -2.6 °C. Unopened, it has a shelf life of 3 years when stored at 15 to 25 °C. It is not classified under GHS/CLP and is not a dangerous good, which simplifies storage, handling and dispatch in day-to-day laboratory work, without the need for additional dangerous goods labelling. Avoid contamination, particularly with trace-grade solutions With a buffer solution low in trace metals, cleanliness during handling is particularly important; otherwise, the advantage of trace-grade quality is quickly lost. Once removed, buffer solution should therefore not be poured back into the bottle, as even small amounts of contamination from the electrode or the measurement environment can alter both the pH value and the trace metal content of the remaining volume. For daily use, it is recommended to use a clean, separate calibration vessel, into which only as much buffer solution as is required for the current calibration is poured. The bottle itself should be kept tightly sealed and stored at a temperature between 15 and 25 °C to ensure that the documented accuracy of ± 0.03 pH is maintained until the end of the three-year shelf life. Typical applications The pH 10.01 Trace technical buffer solution is used wherever pH electrodes need to be calibrated in the alkaline range and the absence of trace metals is important, not only for a one-off calibration but as an integral part of ongoing quality assurance: Alkaline calibration point in water and wastewater analysis Process control for alkaline cleaning and washing solutions in industry Laboratories carrying out trace metal analysis, where a low-metal calibration solution prevents contamination Research and teaching, as a third reference point alongside pH 7 and pH 4 Commissioning and functional testing of new pH electrodes prior to first use Technical details Buffer systemSodium carbonate, sodium hydrogen carbonate (carbonate buffer), trace-grade (low in trace metals) pH value at 25 °C10.01 Accuracy± 0.03 pH Density at 20 °C1.01 g/cm³ Melting point-2.6 °C Shelf life when unopened3 years Storage temperature15 to 25 °C GHS/CLP classificationNot classified, not a dangerous good Scope of delivery 1 bottle of WTW technical buffer solution pH 10.01 Trace in the selected container size (250 ml or 1,000 ml) Individual requirements & procurement service For complete 3-point calibration, we also offer the same technical buffer solution with pH 7.00 and pH 4.01, as well as suitable pH electrodes. For larger quantities, custom container sizes or enquiries regarding the appropriate calibration solution, our procurement service will be happy to assist you.
Content: 1000 ml (€4.60 / 100 ml)
WTW SenTix ORP redox electrode with platinum measuring element, liquid electrolyte, S7 plug-in head, 103648
The WTW SenTix ORP is a redox electrode made of glass with an S7 plug head for laboratory use. It measures redox potentials in mV using a platinum disc as the measuring element. The shaft is 120 mm long and has a diameter of 12 mm; the junction is made of ceramic. The reference electrolyte can be refilled.Measuring element and reference systemThe measuring element is a platinum disc (4 mm), the reference electrolyte is KCl 3 mol/l, Ag+-free. The measured quantity is the voltage in mV; this electrode does not have a pH measuring range. The electrode can be used at sample temperatures of 0 to 100 °C. A temperature sensor is not fitted. The refill opening remains open during measurement. For argentometry, WTW offers the SenTix Ag in the same shaft.Conversion to the standard hydrogen electrodeThe measured voltage refers to the Ag/AgCl reference electrode of the electrode. It is converted to the standard hydrogen electrode using the equation UH = UMeas + URef. For the SenTix ORP, the WTW manual specifies URef = +224 mV at 0 °C, +207 mV at 25 °C and +180 mV at 60 °C. The redox buffer solution RH 28, with UH = 427 mV, is also available for checking the electrode.Typical applications according to WTWRedox measurements in the laboratoryChecking the electrode using the RH 28 redox buffer solutionConnection, storage and careBefore the first measurement, remove the wetting cap; gas bubbles behind the membrane can be removed by shaking. The electrode has an S7 plug head and is supplied without a cable. Depending on the measuring instrument, one of the WTW connection cables AS/DIN (1 m, 108110), AS/DIN-3 (3 m, 108112) or AS/BNC (1 m, 108114) fits. During short measurement breaks, the electrode is immersed in reference electrolyte (3 mol/l KCl, Ag+-free). Overnight and for longer periods, it stays in the wetting cap, filled with reference electrolyte, with the refill opening closed. According to WTW, storing it dry or in deionised water can cause permanent damage. If the cap has dried out, the electrode needs at least 24 hours in reference electrolyte.Technical detailsTyperedox electrode, analogueMeasuring elementplatinum disc (4 mm)Measured quantityVoltage in mVShaft materialGlassShaft length / shaft diameter120 mm / 12 mmReference electrolyteKCl 3 mol/l, Ag+-free, refillableJunctionCeramicTemperature range0 to 100 °CTemperature sensorNoneConnectionS7 plug headCableNo cableScope of delivery1 WTW SenTix ORP electrode with wetting capDropper bottle for refilling (included according to the WTW instructions)No connection cable in the scope of deliveryAccessories and procurement serviceConnection cables (AS/DIN, AS/DIN-3, AS/BNC), reference electrolyte KCl 3 mol/l and the redox buffer solution RH 28 are also available. Enquiries regarding other SenTix electrodes go through the procurement service.
WTW SenTix H analogue special-purpose pH electrode, ground-glass diaphragm, S7 connector, 103644
With the WTW SenTix H, the user sets the electrolyte outflow themselves: a thread on the ground joint diaphragm can be adjusted with the special key, which is included according to the WTW instructions. The analogue glass electrode is refillable and has an S7 plug head. WTW names it for highly alkaline samples and for samples with a high salt concentration.Adjustable ground joint instead of a fixed junctionThe glass shaft has a diameter of 12 mm; the membrane is cylindrical. The reference electrolyte is 3 mol/l KCl, Ag+-free. The refill opening remains open during calibration and measurement, with the electrolyte level at least 2 cm above the sample level. With the ground joint diaphragm, the minimum immersion depth also has to be observed. How far the ground joint is opened determines the electrolyte outflow; the adjustment is described in the WTW instructions. The membrane resistance is below 2 GΩ; measurements are taken from 0 to 14 pH.Typical applications according to WTWHighly alkaline samples and diluted alkalisSamples with a high salt concentrationEmulsions and suspensionsSulphide-containing liquidsCooling water, dye solutions and electroplating bathsBleaching lyeConnection and alternativesThe electrode is supplied without a cable. Depending on the measuring instrument, one of the WTW connection cables AS/DIN (1 m, 108110), AS/DIN-3 (3 m, 108112) or AS/BNC (1 m, 108114) fits. A temperature sensor is not built in; the temperature is either entered on the measuring instrument or measured using an external sensor. For low-ionic-strength media, WTW offers the SenTix HW with the same design.Storage and careBefore taking the first measurement, remove the wetting cap; gas bubbles behind the membrane can be removed by shaking. For short measurement breaks, immerse the electrode in reference electrolyte (KCl 3 mol/l, Ag+-free) with the refill opening open. Overnight and for longer periods, it stays in the wetting cap, filled with reference electrolyte, with the refill opening closed. According to WTW, storing the electrode in a dry state or in deionised water can cause permanent damage. If the cap has dried out, the electrode needs at least 24 hours in reference electrolyte. As with any pH electrode, strong acids and alkalis, hydrofluoric acid, organic solvents, oils, fats and proteins shorten its service life.Technical detailsTypepH electrode, analogue, special electrode with ground jointShaft materialGlassShaft length / Shaft diameter170 mm / 12 mmElectrolyteKCl 3 mol/l, Ag+-free, refillableJunctionGround joint, adjustableMembrane shapeCylindricalpH measuring range0 to 14Membrane resistance< 2 GΩTemperature range0 to 60 °CUse according to WTWHighly alkaline samples, high salt concentrationTemperature sensorNoneConnectionS7 plug headCableNo cableScope of delivery1 WTW SenTix H pH electrode with wetting capSpecial key for the ground joint (included according to the WTW instructions)Dropper bottle for refilling (included according to the WTW instructions)No connection cable in the scope of deliveryAccessories and procurement serviceConnection cables (AS/DIN, AS/DIN-3, AS/BNC), KCl 3 mol/l reference electrolyte and buffer solutions for calibration are also available. The procurement service can answer any questions regarding the appropriate ground-joint electrode.
WTW SenTix 20 plastic pH electrode with gel electrolyte, S7 connector, 103630
Measuring pH in wastewater, aquariums or swimming pools should not depend on a refilling routine. The WTW SenTix 20 features a plastic shaft and a gel electrolyte which, according to WTW, is not refilled. The electrode is low-maintenance. The pH measuring range extends from 0 to 14, and it can be used at sample temperatures of 0 to 80 °C.Gel electrolyte and fibre junctionThe shaft is made of PPE/PS, is 120 mm long and has a diameter of 12 mm. The membrane is cylindrical; its resistance at 25 °C is less than 1 GΩ. According to WTW, the fibre junction prevents blockages. There is no need to monitor or top up the electrolyte level. If the electrolyte is meant to be refillable, the SenTix 51 and 52 with liquid electrolyte and a ceramic junction in a plastic shaft are the alternative.Connection and temperature measurementThe SenTix 20 has an S7 plug head and is supplied without a cable. Depending on the measuring instrument, one of the WTW connection cables AS/DIN (1 m, 108110), AS/DIN-3 (3 m, 108112) or AS/BNC (1 m, 108114) fits. If there is no built-in sensor, the temperature is entered on the measuring instrument or measured using an external sensor. The gel electrodes in this range differ in plug, cable length and temperature sensor. You should therefore establish which input the measuring instrument has before placing your order.Typical applications according to WTWWhen taking samples from water bodies, at the edge of a pool or from a wastewater pipe, what counts is an electrode that is quickly ready for use. WTW names the following media for this series:Electroplating effluent, industrial wastewater and wastewater in generalAquarium and swimming pool waterGroundwater, lake water, surface water and seawaterHousehold cleanersStorage and careBefore the first measurement, remove the wetting cap; gas bubbles behind the membrane can be removed by shaking. For short measurement breaks, immerse the electrode in reference electrolyte (3 mol/l KCl, Ag+-free). Overnight and for longer periods, it stays in the wetting cap, filled with the same electrolyte. According to WTW, storing the electrode dry or in deionised water can cause permanent damage. If the cap has dried out, the electrode needs at least 24 hours in reference electrolyte. As with any pH electrode, strong acids and alkalis, hydrofluoric acid, organic solvents, oils, fats and proteins shorten its service life.Technical detailsTypepH electrode, analogue, gel electrolyteShaft materialPlastic (PPE/PS)Shaft length / Shaft diameter120 mm / 12 mmElectrolyteGel, non-refillableReference systemSilver/silver chlorideJunctionFibreMembrane shapeCylindricalpH measuring range0 to 14Temperature range0 to 80 °CMembrane resistance< 1 GΩ at 25 °CTemperature sensorNoneConnectionS7 plug headCableNo cableScope of delivery1 WTW SenTix 20 pH electrode with wetting capNo connection cable in the scope of deliveryAccessories and procurement serviceConnection cables (AS/DIN, AS/DIN-3, AS/BNC), reference electrolyte KCl 3 mol/l for the wetting cap and buffer solutions for calibration are also available. Enquiries regarding other SenTix models or larger quantities go through our procurement service.
WTW SenTix 51 pH Electrode with Liquid Electrolyte and Temperature Sensor, Plastic Shaft, 1 m Cable, 103651
A plastic shaft does not necessarily mean that the electrolyte is permanently sealed in. The WTW SenTix 51 is a pH electrode with a plastic shaft, liquid reference electrolyte and a built-in temperature sensor. The electrolyte can be refilled. WTW names field and laboratory routine as its areas of use, from drinking water through mineral water and fruit juice to aquariums.Refillable with a ceramic junctionThe reference electrolyte is 3 mol/l KCl, Ag+-free. The refill opening remains open during calibration and measurement. According to the WTW instructions, a dropper bottle for refilling is included. According to WTW, a liquid electrolyte means fast response times; the junction is made of ceramic. The shaft is 120 mm long, has a diameter of 12 mm and is described, depending on the WTW source, as polyamide or, more generally, as plastic. The membrane is cylindrical; its resistance at 25 °C is less than 1 GΩ. Measurements are taken from 0 to 14 pH at 0 to 80 °C.Temperature sensor and plugThe SenTix 51 has a permanently attached 1 m cable with a waterproof DIN plug (DIN 19262). The built-in NTC sensor (30 kΩ) measures the sample temperature for temperature compensation. The sensor is connected to the 4 mm banana plug.Storage and careFor short measurement breaks, immerse the electrode in reference electrolyte (3 mol/l KCl, Ag+-free) with the refill opening left open. Overnight and for longer periods, it stays in the wetting cap, filled with reference electrolyte, with the refill opening closed. According to WTW, storing the electrode in a dry state or in deionised water can cause permanent damage. If the cap has dried out, the electrode needs at least 24 hours in reference electrolyte. As with any pH electrode, strong acids and alkalis, hydrofluoric acid, organic solvents, oils, fats and proteins shorten its service life.When another SenTix model fits betterIf you do not wish to refill the electrode, you can use the SenTix 41 and 42 gel electrodes, which have the same sensor and shaft. For samples up to 100 °C, a glass shaft is an option, for example the SenTix 81 and 82 with a platinum wire junction.Typical applications according to WTWDrinking water and mineral waterFruit juice, vegetable juice and wineAquarium and swimming pool waterLake water, surface water and seawaterTechnical detailsTypepH electrode, analogue, liquid electrolyteShaft materialPlasticShaft length / Shaft diameter120 mm / 12 mmElectrolyteKCl 3 mol/l, Ag+-free, refillableJunctionCeramicMembrane shapeCylindricalpH measuring range0 to 14Temperature range0 to 80 °CMembrane resistance< 1 GΩ at 25 °CTemperature sensorNTC 30 kΩ, built-inConnectionDIN plug (DIN 19262), waterproof, and 4 mm banana plugCable1 m fixed cableScope of delivery1 WTW SenTix 51 pH electrode with wetting capDropper bottle for refilling (included according to the WTW instructions)1 m fixed cable, permanently attached to the electrodeAccessories and procurement serviceKCl 3 mol/l reference electrolyte for refilling and buffer solutions for calibration are also available. For other versions or larger quantities, the procurement service is the quickest option.
WTW SenTix Sur pH surface electrode with flat membrane, glass shaft, S7 connector, 103646
A flat membrane does not measure within the sample, but on its surface. The WTW SenTix Sur is a pH surface electrode for moist samples such as leather, paper and skin. The membrane is flat and, according to WTW, impact-resistant. The shaft is made of glass, is 120 mm long and has a diameter of 12 mm. The measuring range is 2 to 13 pH; the sample temperature may range from 0 to 50 °C.Flat membrane and annular gapThe flat membrane rests on the sample surface. An annular gap serves as the junction, an open junction that, according to WTW, is insensitive to contamination and easy to clean. The reference electrolyte is a polymer (Referid). The electrode is low-maintenance and is not refilled. The membrane resistance is less than 1 GΩ.Typical applications according to WTWSurface measurements on damp samples are the main application. WTW also cites applications in cosmetics, the pharmaceutical industry and biology.LeatherPaperSkinWhen another SenTix model fits betterIf the electrode is to penetrate the sample, for example in cheese, creams or toothpaste, WTW offers the SenTix Sp with a spear-shaped membrane and the same measuring range of 2 to 13 pH. For liquid samples in a beaker, there are glass electrodes with liquid electrolyte, such as the SenTix 60 with a range of 0 to 14 pH.Connection and temperatureThe SenTix Sur has an S7 plug head and is supplied without a cable. Depending on the measuring instrument, one of the WTW connection cables AS/DIN (1 m, 108110), AS/DIN-3 (3 m, 108112) or AS/BNC (1 m, 108114) fits. A temperature sensor is not fitted. The temperature range ends at 50 °C; this should be taken into account when measuring warm samples.Storage and careDuring measurement breaks, the electrode should be immersed in reference electrolyte (KCl 3 mol/l, Ag+-free). Overnight and for longer periods, it stays in the wetting cap, filled with the same electrolyte. According to WTW, storing it dry or in deionised water can cause permanent damage. If the cap has dried out, the electrode needs at least 24 hours in reference electrolyte. As with any pH electrode, strong acids and alkalis, hydrofluoric acid, organic solvents, oils, fats and proteins shorten its service life.Technical detailsTypepH surface electrode, analogueShaft materialGlassShaft length / Shaft diameter120 mm / 12 mmElectrolytePolymer (Referid), non-refillableJunctionAnnular gapMembrane shapeFlatpH measuring range2 to 13Temperature range0 to 50 °CMembrane resistance< 1 GΩTemperature sensorNoneConnectionS7 plug headCableNo cableScope of delivery1 WTW SenTix Sur pH electrode with wetting capNo connection cable in the scope of deliveryAccessories and procurement serviceConnection cables (AS/DIN, AS/DIN-3, AS/BNC), KCl 3 mol/l reference electrolyte and buffer solutions for calibration are also available. The procurement service can answer any further questions regarding surface measurements.
WTW TFK 325 temperature probe for aqueous solutions, 1 m cable, 102280
The pH value of a sample depends on its temperature, and electrodes without their own sensor do not indicate this temperature. This is what the WTW TFK 325 is designed for. It measures the temperature in aqueous solutions and transmits it to the meter, which then automatically compensates for it.Why the probe is necessaryThe slope of a pH measuring cell changes with temperature. A meter can only compensate for this effect if it knows the sample temperature. The temperature of the sample should therefore be measured at the point where the electrode is located, and the probe belongs in the sample too.Design and connectionThe sensor has a 1 m long fixed cable with a waterproof connector, so there is no need to purchase a separate cable. You should check before ordering whether the temperature input on your meter is compatible with the TFK 325.For electrodes without their own temperature sensorAutomatic temperature compensation is used for pH, redox and ISE measurements. An example: The SenTix 62, for instance, is a glass electrode without a temperature sensor. The SenTix ORP redox electrode also does not have a sensor. The TFK 150 is also available from the same sensor range.Typical applicationsAutomatic temperature compensation for pH, redox and ISE measurements in aqueous solutionsExternal temperature probe on conductivity cells and on the D 300/pH flow-through cellTechnical detailsTypeTemperature sensor (NTC) for automatic temperature compensationApplication mediumaqueous solutionsCable1 m fixed cable with waterproof plugScope of delivery1 WTW TFK 325 temperature probe with 1 m cableIndividual requirements and procurement serviceYou can check whether the temperature input on your meter is compatible with the TFK 325 before placing your order. Please direct any enquiries regarding this or suitable pH electrodes to our procurement service.
WTW SenTix 52 pH Electrode with Liquid Electrolyte and Temperature Sensor, Plastic Shaft, BNC Connector, 1 m Cable, 103652
A plastic shaft does not necessarily mean that the electrolyte is permanently sealed in. The WTW SenTix 52 is a pH electrode with a plastic shaft, liquid reference electrolyte and a built-in temperature sensor. The electrolyte can be refilled. WTW names field and laboratory routine as its areas of use, from drinking water through mineral water and fruit juice to aquariums.Refillable with a ceramic junctionThe reference electrolyte is 3 mol/l KCl, Ag+-free. The refill opening remains open during calibration and measurement. According to the WTW instructions, a dropper bottle for refilling is included. According to WTW, a liquid electrolyte means fast response times; the junction is made of ceramic. The shaft is 120 mm long, has a diameter of 12 mm and is described, depending on the WTW source, as polyamide or, more generally, as plastic. The membrane is cylindrical; its resistance at 25 °C is less than 1 GΩ. Measurements are taken from 0 to 14 pH at 0 to 80 °C.Temperature sensor and plugThe SenTix 52 has a permanently attached 1 m cable with a BNC plug. The built-in NTC sensor (30 kΩ) measures the sample temperature for temperature compensation. The sensor is connected to the 4 mm banana plug.Storage and careFor short measurement breaks, immerse the electrode in reference electrolyte (3 mol/l KCl, Ag+-free) with the refill opening left open. Overnight and for longer periods, it stays in the wetting cap, filled with reference electrolyte, with the refill opening closed. According to WTW, storing the electrode in a dry state or in deionised water can cause permanent damage. If the cap has dried out, the electrode needs at least 24 hours in reference electrolyte. As with any pH electrode, strong acids and alkalis, hydrofluoric acid, organic solvents, oils, fats and proteins shorten its service life.When another SenTix model fits betterIf you do not wish to refill the electrode, you can use the SenTix 41 and 42 gel electrodes, which have the same sensor and shaft. For samples up to 100 °C, a glass shaft is an option, for example the SenTix 81 and 82 with a platinum wire junction.Typical applications according to WTWDrinking water and mineral waterFruit juice, vegetable juice and wineAquarium and swimming pool waterLake water, surface water and seawaterTechnical detailsTypepH electrode, analogue, liquid electrolyteShaft materialPlasticShaft length / Shaft diameter120 mm / 12 mmElectrolyteKCl 3 mol/l, Ag+-free, refillableJunctionCeramicMembrane shapeCylindricalpH measuring range0 to 14Temperature range0 to 80 °CMembrane resistance< 1 GΩ at 25 °CTemperature sensorNTC 30 kΩ, built-inConnectionBNC plug and 4 mm banana plugCable1 m fixed cableScope of delivery1 WTW SenTix 52 pH electrode with wetting capDropper bottle for refilling (included according to the WTW instructions)1 m fixed cable, permanently attached to the electrodeAccessories and procurement serviceKCl 3 mol/l reference electrolyte for refilling and buffer solutions for calibration are also available. For other versions or larger quantities, the procurement service is the quickest option.
WTW SenTix 62 glass pH electrode with liquid electrolyte, refillable, BNC, 1 m cable, 103641
WTW lists a wide range of applications for these glass electrodes: from diluted acids and emulsions through to beer, milk and fruit juice, right up to serum and urine. The WTW SenTix 62 features a glass shaft, a refillable liquid electrolyte and a platinum wire junction. It measures from 0 to 14 pH at sample temperatures of 0 to 100 °C. If there is no built-in sensor, the temperature is entered on the measuring instrument or measured using an external sensor.Platinum wire junction and conical membraneThe glass shaft is 120 mm long and has a diameter of 12 mm. According to WTW, the platinum wire junction ensures optimum electrolyte flow without blockages. The membrane is conical in shape; according to WTW, it is impact-resistant and easy to clean. The membrane resistance at 25 °C is less than 600 MΩ. The reference system is 3 mol/l KCl, Ag+-free and refillable. According to WTW, the liquid electrolyte enables fast response times.Typical applications, according to WTWDiluted acids, salt solutions, emulsions and suspensionsCooling water, dye solutions and electroplating bathsDrinking water, groundwater, swimming pool water, lake water, surface water and seawaterSoil, paper and coffee extractsBeer, lemonade, fruit juice, vegetable juice, wine, mineral water, milk and vinegarHair dye, mouthwash and household cleanersEnzyme solutions, gastric juice, infusion solutions, protein-containing liquids, serum, Tris buffer solutions and urine (pharmaceuticals, biology, medicine)ConnectionThe SenTix 62 has a permanently attached 1 m cable with a BNC plug. The variants in this series differ only in terms of plug, cable and temperature sensor; the electrode itself is identical. The choice therefore depends on the input of the measuring instrument. If a longer shaft is needed, the SenTix 91 has a length of 170 mm instead of 120 mm.Refilling and storageThe refill opening remains open during calibration and measurement. A dropper bottle is included, according to the WTW instructions. For short measurement breaks, the electrode is immersed in reference electrolyte (KCl 3 mol/l, Ag+-free) with the refill opening open. Overnight and for longer periods, it stays in the wetting cap, filled with reference electrolyte, with the refill opening closed. According to WTW, storing the electrode in a dry state or in deionised water can cause permanent damage. If the cap has dried out, the electrode needs at least 24 hours in reference electrolyte. As with any pH electrode, strong acids and alkalis, hydrofluoric acid, organic solvents, oils, fats and proteins shorten its service life.Technical detailsTypepH electrode, analogue, liquid electrolyteShaft materialGlassShaft length / shaft diameter120 mm / 12 mmElectrolyteKCl 3 mol/l, Ag+-free, refillableJunctionPlatinum wireMembrane shapeConicalpH measuring range0 to 14Temperature range0 to 100 °CMembrane resistance< 600 MΩ at 25 °CTemperature sensorNoneConnectionBNC plugCable1 m fixed cableScope of delivery1 WTW SenTix 62 pH electrode with wetting capDropper bottle for refilling (included according to the WTW instructions)1 m fixed cable with BNC plug, permanently attached to the electrodeAccessories and procurement serviceReference electrolyte KCl 3 mol/l for refilling and buffer solutions for calibration are also available. If you require a different version or multiple electrodes, please enquire via the procurement service.