WTW digital IDS pH insertion electrode SenTix Sp-T 900-P, plastic shaft, 103766

An electrode that is pushed into cheese, meat or cream has to be pointed and sturdy. For this, the WTW SenTix Sp-T 900-P has a spear-shaped membrane, which is impact-resistant according to WTW, and a plastic shaft made of PPE/PS. It is a digital IDS electrode, and its calibration data is stored in the sensor. The pH measuring range is only 2 to 13, and the sample temperature may be 0 to 80 °C.

Penetration measurement in semi-solid media

For the measurement, the tip with the hole junction must be fully inserted in the sample. Only the shaft is immersed. For penetration measurements, the electrode is not moved, and one waits until the measured value is stable. Between two measurements, the electrode is rinsed with deionised water and gently patted dry.

Polymer electrolyte and hole junction

The reference system is a Referid polymer electrolyte, AgCl-free, with a polymer filling that lasts a lifetime according to WTW. It is not refilled, and the electrode is low-maintenance. The junction is a simple hole junction. According to WTW, the membrane resistance is below 400 MΩ. The stepped shaft is 65/25 mm long and has a diameter of 15/5 mm. An NTC temperature sensor (30 kΩ) is built in, and the IDS electronics measure with pH ±0.004, ±0.2 mV, ±0.1 °C (±1 digit in each case).

Typical applications according to WTW

• Creams, lotions, hair gel, make-up and toothpaste
• Meat, sausage, fish, cheese, butter and margarine
• Yoghurt, quark, mayonnaise as well as bread, fruit and vegetables

According to WTW, the plastic shaft is also suitable for use in the field.

Connection

The SenTix Sp-T 900-P has an IDS plug head, and according to WTW the plug connection is waterproof and lockable. For operation, an IDS connection cable or the IDS WLM-S wireless adapter is needed. Neither is included. For penetration measurements in a production environment, the route to the measuring instrument determines the cable length.

Storage and cleaning

During measurement breaks, the electrode is immersed in reference electrolyte (KCl 3 mol/l, Ag+-free); overnight, it stays in the wetting cap filled with it. According to WTW, dry storage can permanently damage it. Grease and oil can be removed with water containing detergent, limescale and hydroxide deposits with citric acid (10 % by weight). Hydrofluoric acid, hot phosphoric acid and strongly alkaline solutions destroy the glass membrane. After cleaning, the electrode is conditioned in reference electrolyte for at least one hour and recalibrated.

Technical details

Scope of delivery

• 1 WTW SenTix Sp-T 900-P pH electrode with wetting cap
• Operating instructions
• No connection cable and no wireless adapter in the scope of delivery

Regulatory information

As 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 service

Also available are connection cables AS/IDS from 1.5 m (903850) to 100 m (903859), the IDS WLM-S wireless adapter, reference electrolyte KCl 3 mol/l and buffer solutions for calibration. Enquiries about further special electrodes go through the procurement service.