WTW SenTix 51 PH Electrode with Liquid Electrolyte and Temperature Sensor, Plastic Shaft, 1 m Cable, 103651
€256.00
% Manufacturer's RRP: €284.00 9% below manufacturer's RRP
- Refillable reference system consisting of 3 mol/l KCl, Ag+-free, with ceramic diaphragm
- Integrated NTC temperature sensor (30 kOhm)
- Polyamide shaft, 120 mm long, 12 mm in diameter
- 1 m fixed cable with waterproof DIN plug and 4 mm banana plug
- Measuring range 0 to 14 pH, temperature range 0 to 80 °C
- Dropper bottle with reference electrolyte included in the scope of delivery
Product information "WTW SenTix 51 PH Electrode with Liquid Electrolyte and Temperature Sensor, Plastic Shaft, 1 m Cable, 103651"
The WTW SenTix 51 has a plastic shaft and a reference electrolyte that can be topped up via a refill port. A ceramic diaphragm is used. It also features an NTC sensor in the shaft and a 1 m long fixed cable.
Refillable system with ceramic diaphragm
The reference system consists of reference electrolyte (3 mol/l KCl, Ag⁺-free). Due to the way it works, a small amount flows from the reference system through the diaphragm into the sample during operation; if the level drops too low, it can be topped up via the refill port. The supplied dropper bottle is intended for this purpose. During calibration and measurement, the refill port remains open, and the electrolyte level should be at least 2 cm above the sample level.
Shaft and connector
The shaft is made of polyamide and measures 120 x 12 mm. The 1 m long fixed cable has a waterproof DIN plug and a 4 mm banana plug. The manufacturer classifies the SenTix 51 to 57 series as suitable for field use. The SenTix 81 is suitable for measurements up to 100 °C in a glass shaft.
pH and temperature in a single measuring chain
The integrated NTC 30 kOhm sensor supplies the measuring instrument with the sample temperature for automatic compensation. The pH measurement range is from 0 to 14; the permissible temperature range is 0 to 80 °C, and the membrane resistance is less than 1 GΩ. If your instrument has a BNC connector instead of a DIN connector, you will find the same model as the SenTix 52.
Preparation, storage and cleaning
Before the first measurement, open the filling port, remove the rinsing cap and shake the measuring chain to dispel any air bubbles behind the membrane. For overnight storage, place the electrode in the wetting cap filled with reference electrolyte and close the refill opening. A pepsin cleaning solution removes protein-containing deposits, whilst water containing washing-up liquid removes grease and oil. After each cleaning, the electrode must be conditioned for at least one hour and recalibrated.
Typical applications
- Drinking water, mineral water and aquarium water
- Swimming pool water
- Lake water, surface water and seawater
- Fruit juice, vegetable juice and wine
Technical details
| Type | pH electrode with liquid electrolyte and temperature sensor |
| Sensor design | Cylinder |
| Shaft material | Plastic (polyamide) |
| Shaft length / Shaft diameter | 120 mm / 12 mm |
| Diaphragm | Ceramic |
| Reference system | KCl 3 mol/l, Ag⁺-free, refillable |
| pH measuring range | 0 to 14 pH |
| Temperature range | 0 to 80 °C |
| Membrane resistance | < 1 GΩ |
| Temperature sensor | NTC 30 kOhm, integrated |
| Connection | 1 m fixed cable with waterproof DIN plug and 4 mm banana plug |
| Standards | EU Declaration of Conformity (RoHS Directive 2011/65/EU), WEEE marking |
Scope of delivery
- 1 WTW SenTix 51 pH measuring chain with rinsing cap
- 1 dropper bottle with reference electrolyte for refilling
Individual requirements and procurement service
Replenishment of KCl-250 reference electrolyte (order no. 109705), PEP/pH pepsin cleaning solution (109648), buffer solutions and the plastic reinforcement A pHLab/K are available on request. Our procurement service is available to assist with further SenTix models and selection based on the measuring instrument.