The CPA-325S is SIMEX's hydrostatic level probe built for liquids that carry impurities and suspended solids — the sludge, sediment and abrasive particles that stop a standard probe from giving a trustworthy reading.

Why does a wastewater level probe need a 48 mm diaphragm?

A conventional small diaphragm sits flush with the housing, so sediment settles on it and the reading drifts as the effective area changes. The CPA-325S uses a thick 48 mm 316L diaphragm set back in a 76 mm separator, which keeps sludge and abrasive particles like sand from packing against the sensing surface — the probe keeps measuring in fermentation chambers, settling tanks and pumping stations where a standard unit would need monthly cleaning. When service is due, a gentle water jet is enough to wash the membrane; the sensor and stainless housing also shrug off the mechanical knocks of installation and retrieval.

What does a 2-wire loop change in a lift station?

Level loops in wastewater plants often run hundreds of metres to a control panel, and every extra conductor is one more failure point and one more channel on the I/O rack. The CPA-325S transmits on a standard 2-wire 4–20 mA loop powered from 8–32 VDC, so it drops straight into an existing two-wire channel — with 3-wire 0–20 mA, 0–5 V or 0–10 V output available when the panel expects a voltage signal. Rated IP68 and -40 to +125 °C, it sits submerged in the tank year-round without needing an enclosure.

• Measuring range 0–1 to 0–250 mH2O, accuracy ±0.35%
• 2-wire 4–20 mA standard, 3-wire mA/V options
• Ø48 mm 316L diaphragm in Ø76 mm separator — anti-blockage design
• IP68, -40 to +125 °C, stainless housing
• PVC, PUR, FEP or TPE-U cable options, 3-year warranty

Against a compact pressure probe sized for clean water, the CPA-325S trades a few millimetres of diameter for a membrane that survives sludge — the reason wastewater operators stop cleaning sensors and start trusting them.