Peracetic acid concentration sensor P9.3

Overview
The Germany-made P9.3 PAA sensor adopts a membrane-covered amperometric 2-electrode system to accurately measure peracetic acid concentration in aqueous solutions. It delivers temperature-compensated analog outputs and Modbus RTU digital signals. Calibration is possible via downstream devices or by direct one-key calibration with compatible transmitters. The sensor tolerates water temperatures up to 60 °C, uses a chemical- and surfactant-resistant elastomer membrane, and provides low-maintenance operation. Typical accuracy is <2–3% (for the 2000 mg/L range) and response time T90 varies from approx. 45 s to 3.5 min depending on temperature. IP65/IP68 protection options, EMC and RoHS compliance, and flexible connectivity make it suitable for industrial water treatment applications such as bottle washing machines and CIP plants.

Special features

• Membrane-covered amperometric 2-electrode system
• High temperature tolerance up to 60 °C (measuring water)
• Resistant elastomer membrane against chemicals and surfactants
• Temperature-compensated analog and Modbus RTU digital outputs

Applications
Industrial water treatment: electroplating, pharmaceutical, food & beverage, dairy and chemical industries; examples include bottle washing machines and CIP plants.

Process conditions

• Max. measuring water temperature: 60 °C (no ice crystals in the measuring water)
• Max. ambient temperature: 55 °C
• Max. pressure: 1 bar (installation-dependent; operation with retaining ring: -1.0 bar / -0.5 bar at low flow; avoid pressure surges and vibrations)
• Flow rate (face velocity): approx. 15–30 L/h in flow cell; small flow rate dependence

Technical specification (summary)

• Measurement parameter: Peracetic acid (PAA)
• Measuring ranges / resolution: 0–200 ppm (0.1 ppm); 5–2000 ppm (1 ppm); 0.005–2 % (20000 ppm: 0.001 % / 10 ppm)
• Accuracy: <2–3% (for 2000 mg/L range)
• Response time (T90): approx. 45 s (at 50 °C) to 3.5 min (at 10 °C)
• Measuring water temperature: 0…+60 °C
• Ambient temperature: 0…+55 °C
• Temperature compensation: automatic via integrated sensor (avoid sudden temperature changes)
• Max. allowed working pressure: see process conditions (installation-dependent)
• pH range: pH 1 – pH 8
• Run-in time: 200 mg/L ~ 3 h; 2000 mg/L ~ 1 h; 20000 mg/L ~ 30 min
• Zero point adjustment: not necessary
• Protection class: IP65 / IP68 options (5‑pole M12 plug-on flange IP68; 2‑pole terminal with mA-hood IP65)
• Materials: elastomer membrane, PEEK, stainless steel 1.4571
• Outputs: temperature-compensated analog signals; Modbus RTU digital signals
• Compliance: EMC, RoHS

Technical specifications

• Model: P9.3
• Measurement: Peracetic acid (PAA)
• Protection: IP65 / IP68
• Connectivity: analog temperature-compensated outputs, Modbus RTU
• Maintenance: low