WTW digital IDS pH electrode SenTix 940, plastic shaft, 1.5 m fixed cable, 103740

The WTW SenTix 940 digital IDS pH electrode is intended for pH measurement in both laboratory and field applications. Designed for use with WTW IDS multiparameter meters, this digital electrode enables reliable signal transmission and documentation.

Intelligent IDS sensor technology and digital signal processing

The SenTix 940 uses IDS (Intelligent Digital Sensors) technology. Unlike conventional analogue probes, the sensitive analogue voltage signal is digitised and calibrated directly within the internal sensor assembly. This transient signal processing reduces electromagnetic interference. An integrated data memory permanently stores the sensor’s specific serial number as well as a calibration history for up to 10 calibrations. Thanks to the intelligent QSC (Quality Sensor Control) function, the sensor continuously assesses its current status and displays this directly on the measuring instrument, supporting process reliability with every measurement.

Low-maintenance gel electrolyte and robust materials engineering

The material design is consistently optimised for mechanical resilience and minimal maintenance intervals. The electrode features a plastic shaft made of PPE/PS, which protects the glass membrane against mechanical impact during field measurements. A tried-and-tested gel electrolyte, combined with a fibre diaphragm, serves as the reference system. This low-maintenance system eliminates the need to top up liquid KCl electrolyte and reduces the risk of diaphragm blockages, which significantly extends the sensor’s service life in multi-user operation.

Integrated temperature compensation and process-reliable fixed cable

To ensure precise measurement results, the SenTix 940 features a built-in 30 kOhm NTC temperature sensor, which provides automatic, real-time temperature compensation of the pH value. The connection to the IDS meter is via a permanently fitted, 1.5-metre-long cable with a waterproof, digital IDS connector. The IDS plug connection is watertight and locked.

Technical details

Measurement & sensor technology

• Sensor type: Digital IDS pH electrode
• Model: SenTix 940
• pH measurement range: 0 to 14 pH
• Temperature element: Integrated NTC 30 kOhm temperature sensor
• Operating temperature range: 0 to 80 °C
• Calibration memory: Integrated memory for up to 10 calibrations
• Sensor evaluation: QSC-compatible (Quality Sensor Control)

Design & dimensions

• Shaft material: Plastic shaft (PPE/PS)
• Electrolyte: Low-maintenance gel electrolyte
• Diaphragm: Fibre diaphragm
• Shaft length: 120 mm
• Shaft diameter: 12 mm
• Connection type: Fixed cable, length 1.5 m with digital IDS plug
• Serial number: Stored electronically within the sensor

Operating conditions

• Maintenance: Low maintenance (no need to top up liquid electrolyte)
• Application: General-purpose aqueous media, laboratory and field measurements, quality control

Scope of delivery

• 1 x WTW SenTix 940 digital IDS pH electrode with 1.5 m fixed cable (MPN: 103740)
• 1 x Wetting cap with storage solution

Important note: pH buffer solutions, cleaning concentrates and the IDS meter itself are not included in the standard scope of delivery and must be ordered separately.

Individual requirements & accessories

To realise the full potential of the WTW SenTix 940, we recommend using it with a compatible WTW MultiLine or inoLab IDS meter. For regular recalibration and to safeguard the metrological chain, we offer WTW technical buffer solutions (pH 4.01, pH 7.00, pH 10.01) in our range. For the proper storage and care of the sensitive glass membrane, we recommend the original KCl storage solution. Please use our technical procurement service to put together your digital measuring station.