Walchem WEL Series pH and ORP Electrodes

The Walchem WEL Series are cost-effective differential pH and ORP electrodes engineered for industrial water-treatment applications. A modular CPVC housing contains all of the electronics, and pH or ORP cartridges connect through a threaded interlock with a double O-ring seal — replacing a cartridge takes minutes with no tools and no need to discard the electronics.

An integral titanium solution ground rod enables differential measurement, delivering prolonged electrode life, stable readings, and resistance to stray voltages and ground-loop interference. Cable runs reach up to 4,000 ft (1,219 m) at 24 VDC, response is better than 90% in under 5 seconds, and a built-in preamplifier or 4-20 mA transmitter feeds Walchem Intuition and WebMaster controllers.

Differential measurement — integral titanium ground rod for stable readings even with stray voltages or ground-loop interference
Modular CPVC housing — electronics stay in the housing when the cartridge is replaced, lowering long-term cost
Tool-free cartridge swap — threaded interlock + double O-ring seal; replace pH or ORP cartridges in minutes
Built-in preamplifier or 4-20 mA transmitter — direct signal into Walchem Intuition / W100 / W600 / W900 / WebMaster controllers
Long cable runs — up to 4,000 ft (1,219 m) at 24 VDC, 24 AWG
Fast response — better than 90% in under 5 seconds
Wide measurement range — 0–14 pH or ±2,000 mV ORP; 0–100 °C; 0–100 psi

Industrial water-treatment systems requiring continuous pH and ORP measurement
Process loops where ground-loop interference or stray voltage compromises conventional electrodes
Applications calling for long cable runs to remote sensor locations

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