pH electrodes & sensors

Choose the electrode for the sample, not just the range. A general-purpose electrode handles aqueous solutions, such as the InLab® Routine, pH 0–14. A slim shaft reaches into small vessels and tubes, as with the InLab® Semi-Micro, pH 0–12. A piercing tip measures in solid and semi-solid samples like cheese, meat or soil, as with the InLab® Solids, pH 1–11. Viscous, oily or protein-rich samples need an electrode built for them, such as the InLab® Viscous. Questions: sales@luminixhealth.com.

The electrode connector must match the socket on your meter, or you need an adapter cable. Common types are S7, which takes a separate cable, as on the InLab® Viscous; MultiPin, which also carries sensor data, as on the InLab® Science Pro-ISM® cell; and BNC, as on the N 6000 BNC electrode. Some electrodes have a fixed BNC plus Cinch cable with an IP67 rating. Others are made for one meter only, such as the InLab® Expert Go for the SevenGo pH meter. Send us your meter model: sales@luminixhealth.com.

Never let the glass membrane dry out. Between measurements, keep the electrode in the storage solution the producer specifies, for example the storage solution, 500 ml, and never in distilled water, which draws ions out of the glass. Rinse with deionised water between samples and blot, do not wipe. When readings get slow, clean according to the contamination: pepsin/HCl removes protein deposits, and thiourea/HCl removes silver sulphide in the diaphragm, each 500 ml. Calibrate again after cleaning.

Replace the electrode when cleaning and recalibration no longer help: the slope stays clearly outside the range your meter accepts, the response stays slow, readings drift, or the glass is cracked or scratched. How long an electrode lasts depends on samples, temperature and care, so there is no fixed lifetime. Keep a log of slope and offset after each calibration to see the decline coming. For pH testers there are spare electrodes, such as the spare electrode for the SD10 pH tester. See all pH electrodes and sensors.

A pH electrode is a glass membrane and a reference. It is a consumable: the glass ages, the junction clogs, and the reading drifts. A refillable electrode and a gel electrode differ in how they are maintained. The connector has to match the meter. The electrode, not the meter, is usually what is wrong.

A pH meter is a voltmeter on a glass electrode. The voltage tracks hydrogen-ion activity, and the electrode is converted to pH only after it is adjusted with buffers of known value. Conductivity measures how well a solution carries a current, which for dilute salts tracks concentration. Dissolved oxygen and titration are further electrodes on the same idea: a sensor, a standard, and a reading that is only as fresh as the calibration. Buffer values and chemical identity sit on PubChem. Accreditation of the calibration laboratory is the field of BELAC and EURAMET.

This shelf belongs to pH & electrochemistry, inside Lab instruments. Luminix Health distributes this range for laboratory use.

The neighbouring shelves are pH meters, Conductivity meters & cells, Dissolved oxygen & multiparameter meters, Titrators & electrochemistry systems and pH & electrochemistry accessories. The category above this shelf is pH & electrochemistry.

Luminix Health distributes this range from the heart of Europe. We deliver across the EU in two to five days if in stock. Standard delivery is free from €250 excl. VAT. Cold-chain goods and dangerous goods under ADR are never included in that free delivery. The terms are in the Shipping Policy. Send a quote request, contact the team, or read who we are. The full brand index is on shop by brand.

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