WTW SenTix HWD PH Electrode with Ground-glass Diaphragm and Temperature Sensor, 170 mm Shaft, 1 m Cable, 103731

The WTW SenTix HWD has a ground diaphragm that can be opened and flushed. It also features a 170 mm long glass shaft, a 30 kOhm NTC sensor and a refillable liquid electrolyte (KCl 3 mol/l, Ag+-free). It measures from 0 to 14 pH and is approved for use between -5 and 100 °C.

Ground-glass diaphragm and spherical membrane

The membrane is spherical, with a membrane resistance of less than 600 MΩ. The ground diaphragm can be opened and rinsed if necessary: to do this, slide the ground sleeve from the ground core towards the shaft whilst turning it slightly. On delivery, the ground sleeve is secured with a heat-shrink sleeve. Before first use, this should be carefully cut open with a sharp knife or scalpel, as the sleeve is made of plastic and can be easily damaged. Next, whilst holding the electrode vertically and keeping the refill opening open, loosen the ground connection by turning it slightly until electrolyte escapes, then replace the sleeve.

Cable and connection

The 1 m long fixed cable has a waterproof DIN plug (coaxial plug to DIN 19262) and a 4 mm banana plug. The sister electrode, the SenTix HW, also has a ground diaphragm, but features an S7 connector head and no temperature sensor. If you do not require a ground-ground diaphragm, the SenTix 82 (platinum wire diaphragm, 0 to 100 °C, shorter shaft, BNC plug instead of a DIN plug) will suffice.

Typical applications

• Emulsions and suspensions, sulphide-containing liquids
• Cooling water, dyeing solutions and electroplating baths
• Boiler feed water, condensate, distilled and fully demineralised water, rainwater and low-ion media
• Salt solutions and soil extracts
• Beer, lemonade, fruit juice, vegetable juice, wine, mineral water, milk, yoghurt and quark
• Coffee extract, honey, jam and vinegar
• Hair dye, mouthwash, shampoo and household cleaners
• Enzyme solutions, gastric juice, infusion solutions, serum, Tris buffer solutions and urine

Refilling and storage

Calibration is carried out in accordance with the meter’s instructions, under stirring conditions similar to those used during measurement. The refill opening remains open during calibration and measurement; the electrolyte level must be at least 2 cm above the sample level; and the ground-glass diaphragm must be completely submerged in the sample. Refill using the enclosed dropper bottle. During breaks, the electrode is placed in the reference electrolyte; overnight, it is placed in the filled rinsing cap with the refill opening closed. Protein deposits can be removed using the pepsin cleaning solution PEP/pH (item no. 109648). After cleaning, the measuring chain is rinsed with deionised water, conditioned in reference electrolyte for at least one hour and recalibrated. Hydrofluoric acid, hot phosphoric acid and strong alkalis destroy the glass membrane. Suitable accessories include the KCl-250 reference electrolyte (item no. 109705), WTW buffer solutions and the A pHLab/K plastic reinforcement (item no. 903841).

Technical details

Scope of delivery

• 1 WTW SenTix HWD pH electrode with rinsing cap
• Drop bottle with reference electrolyte for refilling

Individual requirements and procurement service

Whether you need replacement electrolyte, buffer solutions or advice on whether a ground-glass diaphragm is the right choice for your sample: the procurement service at lt-laborhandel.com/service can advise you and supply the accessories.