Keep your field program moving without downtime. Replacement sensors for the HORIBA U-52 are designed for fast, straightforward field swaps — no complicated rebuilds and no factory service delays. Whether you are replacing a worn sensor or restoring calibration performance, you can install a new element and get back to collecting reliable water quality data the same day.

The U-52 is built so that individual sensing elements are replaced rather than the whole probe. That keeps maintenance costs down and extends the working life of the instrument considerably — a single failed pH element does not take the rest of a working sonde out of service with it.

What is available

• pH sensor (3014057312) — the standard replacement pH element.
• #7113 ToupH pH sensor (3200170923) — reinforced ToupH glass, more resistant to breakage and abrasion. Worth specifying for rough boreholes, silty water and high-turnover field programs.
• ORP sensor (3014046720) — replacement redox potential element.
• DO sensor (3200170924) — replacement dissolved oxygen element.
• Turbidity sensor (3200172803) — replacement turbidity element for the U-52.
• #7210 reference electrode tip (3200043582) — the reference junction. A sluggish, drifting or non-calibrating pH reading is frequently the reference tip rather than the pH element itself.
• Liquid junction cap, 2 pcs (3200043587) — replaceable junction caps, a low-cost wear item that should be changed on a schedule rather than on failure.
• 4-pack — pH, turbidity, ORP and DO together, for a full sensor refresh in one order.

Diagnosing which sensor to replace

• Will not calibrate, or slope out of range — replace the pH element; if the new element behaves the same way, replace the reference tip.
• Slow, drifting or noisy pH — usually the reference tip or a fouled liquid junction, not the pH glass.
• DO reads low or responds slowly — check the membrane cap first; replace the DO element if a fresh membrane does not restore response.
• ORP readings implausible in a known standard — clean the metal surface, then replace the ORP element if verification against a standard still fails.
• Turbidity high at zero, or unstable — inspect and clean the optics and wiper before replacing the turbidity element.

If you need a sensor that is not listed here, please contact us.

Related items

Visit the Horiba U-52 Multiparameter Water Quality Meter page for the handheld unit and cable assemblies. DO membrane caps, probe guards, rubber caps, O-ring sets, wiper rubbers, flow cells, carrying cases and calibration solutions are in the Horiba Parts & Accessories collection, and the #7801 turbidity cell for the U-53 and U-53G is listed with the U-50 Series accessories.