WTW SenTix HW-T 900-P digital IDS pH special electrode, ground-glass diaphragm, 103767

The WTW SenTix HW-T 900-P digital IDS pH special-purpose electrode represents a premium-class electrochemical system solution for high-precision pH measurement in particularly demanding, low-ion or highly viscous media. Designed for use in environmental analysis, the chemical industry and in research and development laboratories, this digital glass electrode excels wherever conventional sensors fail due to insufficient electrolyte contact. When measuring in distilled water, boiler feedwater, organic solvents, emulsions or suspensions, the controlled flow dynamics of the reference system are the primary factor in reliably guaranteeing stable potentials and reproducible results.

Intelligent IDS sensor technology and digital measurement reliability

The mechatronic system architecture of the SenTix HW-T 900-P is based on pioneering IDS (Intelligent Digital Sensors) technology. The highly sensitive analogue voltage signal from the measuring chain is digitised and calibrated directly within the sensor head. This transient signal processing completely eliminates electromagnetic interference, such as that which may be induced by surrounding laboratory equipment, motors or stirring drives. The integrated data memory permanently stores the electrode’s specific serial number as well as a complete history of the last 10 calibrations. The automatic sensor evaluation system QSC (Quality Sensor Control) continuously monitors the electrode’s current condition and displays it on the IDS measuring instrument, guaranteeing the highest level of validity at every test stage.

Adjustable ground diaphragm and refillable liquid reference system

The materials-science-based design is specifically optimised for problematic sample matrices. The electrode features a precise, adjustable ground diaphragm. This ensures a comparatively high and constant flow rate of the liquid electrolyte, thereby achieving excellent electrical contact with the sample medium. Clogging caused by particles, oils or organic precipitates is prevented by the geometry of the ground core in a way that is gentle on the material. A tried-and-tested liquid electrolyte (3 mol/l KCl) serves as the reference system; it can be easily topped up or completely replaced via a sealable opening on the upper glass shaft. This guarantees an extremely fast response time and prevents measurement drifts even in media with low ion content.

Extended glass shaft and universal IDS plug-in head

To ensure thermodynamically correct analyses, the SenTix HW-T 900-P features a built-in 30 kOhm NTC temperature sensor, which is integrated directly into the sensor tip and performs automatic, real-time temperature compensation of the pH value. A key design feature is the extended glass shaft, measuring 165 mm in length, which allows deep immersion into specialised sample vessels, necked flasks or reactors. An outstanding ergonomic feature of this variant is the universal IDS plug-in head. The sensor does not have a permanently attached cable; instead, it can be connected to the measuring station with great flexibility, either via an AS IDS connection cable or completely wirelessly via a WTW radio module. This protects the delicate glass system from mechanical stress caused by cable tension and significantly improves the user’s freedom of movement.

Technical details

Measurement & Sensor Technology

• Sensor type: Digital IDS special-purpose pH electrode
• Model: SenTix HW-T 900-P
• pH measurement range: 0 to 14 pH
• Temperature element: Integrated NTC 30 kOhm temperature sensor
• Operating temperature range: 0 to 100 °C
• Calibration memory: Integrated memory for up to 10 calibrations
• Sensor evaluation: QSC-compatible (Quality Sensor Control)

Design & dimensions

• Shaft material: Highly chemically resistant glass shaft
• Shaft length: 165 mm (extended version)
• Shaft diameter: 12 mm
• Electrolyte: Liquid electrolyte (3 mol/l KCl, refillable)
• Diaphragm: Adjustable ground diaphragm
• Connection head: Universal IDS plug-in head (for AS IDS cable or wireless module)
• Serial number: Stored electronically in the sensor

Operating conditions

• Maintenance: Refillable (KCl liquid replaceable)
• Main applications: Low-ion media (e.g. pure water, distilled water), emulsions, suspensions, organic solutions, deep sample vessels

Scope of delivery

• 1 x WTW SenTix HW-T 900-P digital IDS pH special electrode (MPN: 103767)
• 1 x rinsing cap with KCl storage solution
• 1 x vial of refill electrolyte (3 mol/l KCl)
• 1 x Quality certificate / Quick start guide

Important note: The required IDS connection cable (e.g. AS IDS-1.5), wireless modules, pH buffer solutions and the IDS meter itself are not included in the standard scope of delivery and must be ordered separately.

Individual requirements & accessories

To make full use of the WTW SenTix HW-T 900-P’s full range of functions, we recommend operating it with a compatible WTW MultiLine or inoLab IDS meter. For the mechanical connection, we stock the suitable AS IDS-1.5 cable as well as innovative IDS wireless module systems for cable-free operation. For regular recalibration and to ensure the integrity of the metrological chain, we offer certified WTW technical buffer solutions (pH 4.01, pH 7.00 and pH 10.01). For regular topping up and the proper storage of the grinding system, we recommend the original 3 mol/l KCl solution. Please use our procurement service to put together your bespoke digital measuring station.