Electrochemical chlorine sensor CP4.0

for water treatmentfor process measurementfor wastewater treatment plants

Overview
German-made CP4.0 total chlorine sensor using a microporous hydrophilic osmotic membrane technology that resists chemical interference (mainly from surfactants), reduces pH dependence and is not restricted by water quality. The sensor provides fast response, stable performance, low cost and minimal maintenance while delivering reliable, accurate data.

Key features

• Microporous hydrophilic membrane for selective measurement
• Reduced dependence on pH
• Tolerates surfactants and polluted measuring water
• High tolerance to chemicals and low conductivity
• Requires little maintenance
• Mechanically robust membrane system

Instrument functions and outputs
LCD screen with intelligent Chinese/English menu operation; analog 4-20 mA and digital RS485 outputs; freely settable measurement range; high/low limit alarms; three relay control switches; adjustable hysteresis; multiple electrode auto-calibration methods.

Applications

• Tap water monitoring (typical range 0–2 mg/L)
• Sewage treatment and process water (up to 20 mg/L)
• Seawater and brine (conductivity up to 200 mS/cm)
• Swimming-pool water, drinking water, service water, process water
• Washing of fruit, vegetables and poultry

Ambient and installation conditions

• Maximum temperature: 45 °C
• Maximum pressure: 3 bar
• Minimum conductivity: 10 µS/cm
• Flow in flow chamber: approx. 15–30 l/h
• Protection levels: 5-pole M12 plug-on flange IP68; 5/2-pole terminal with mA-hood IP65

Technical data (table)
Measurement parameters: Total Chlorine, pH (optional)
Measuring ranges: 0.005–0.500 mg/L; 0.005–2.000 mg/L; 0.05–5.00 mg/L; 0.05–10.00 mg/L; 0.05–20.00 mg/L
Lower limit of measurement: 0.005 mg/L (depending on the electrode)
Resolution: 0.001 mg/L or 0.01 mg/L (depending on the measuring range)
Accuracy (@25°C, pH 7.2): Measuring range 2 mg/L: at 0.4 mg/L < 2%; at 1.6 mg/L < 2%; Measuring range 20 mg/L: at 4 mg/L < 1%; at 16 mg/L < 3%
Response time: T90 ≈ 3 minutes
Drift: Approximately -1% per month (after calibration at 25°C and pH = 7.2)
pH range: 4.0 - 12.0 (depending on the electrode)
Operating temperature: 0 - 45 °C
Run-in time (first start-up): approx. 2 h
Conductivity range: 10 µS/cm – 200 mS/cm (brine)
Material: Microporous hydrophilic membrane, PVC-U, PEEK, stainless steel 1.4571

Typical application measurement ranges
Tap water: 0–2 mg/L
Sewage treatment: 0–20 mg/L
Seawater/brine: compatible up to specified conductivities (see conductivity range above)

Technical specifications

• Model: CP4.0
• Measurement: Total chlorine (optional pH)
• Measuring ranges: selectable 0.005 mg/L up to 20 mg/L
• Lower detection limit: 0.005 mg/L (electrode dependent)
• Resolution: 0.001 or 0.01 mg/L
• Response time: ~3 minutes (T90)
• Accuracy examples: <2% at 0.4–1.6 mg/L (range 2 mg/L); <1% at 4 mg/L (range 20 mg/L)
• Drift: ~-1%/month after calibration
• pH operating range: 4.0–12.0 (electrode dependent)
• Operating temperature: 0–45 °C
• Max. pressure: 3 bar
• Conductivity tolerance: 10 µS/cm – 200 mS/cm
• Flow requirement (flow chamber): approx. 15–30 l/h
• Protection rating: M12 IP68 or terminal IP65
• Materials: microporous hydrophilic membrane, PVC-U, PEEK, stainless steel 1.4571