Electrochemical chlorine dioxide sensor CD4.2

for water treatmentfor process measurementdigital

Overview
The German-made chlorine dioxide sensor CD4.2 is a membrane-covered amperometric 2-electrode sensor for ClO₂ measurement. It features automatic temperature compensation and rapid response time, delivering high-resolution results across models. Available with analog and digital outputs (including 4-20 mA versions), it provides galvanic isolation and is offered with IP65/IP68 protection. Suitable for monitoring water disinfection in swimming-pool, drinking, service and process water (measuring water must not contain surfactants). The sensor operates at 0-45 °C, pH 1–12 and up to 1.0 bar. Low slope drift and easy maintenance ensure reliable long-term performance.

Special features

• Membrane-covered amperometric 2-electrode design
• Automatic temperature compensation
• Short / rapid response time
• High resolution (range-dependent)
• Available analog and digital outputs, including 4-20 mA
• Galvanic isolation
• IP65 / IP68 protection options
• Low slope drift, easy maintenance

Applications

• Swimming-pool water monitoring
• Drinking water monitoring
• Service water and process water monitoring (no surfactants in measuring water)

Ambient conditions

• No surfactants in the measuring water
• Maximum temperature: 45 °C
• Maximum pressure: up to 1.0 bar (dependent on mounting / retaining ring)

Technical Specification
Measurement Parameters: Chlorine dioxide
Measuring Ranges: 0.005…0.500 ppm / 0.005…2.000 ppm / 0.05…5.00 ppm / 0.05…10.00 ppm / 0.05…20.00 ppm
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)
Response time: T90 ≈ 15 seconds
Drift: Approximately -1% per month (after calibration at 25 °C and pH = 7.2)
pH range: 1.0 - 12.0 (depending on the electrode)
Operating temperature: 0 - 45 °C
Flow rate: In flow chamber: 15-30 l/h (approx.)
Max. allowable working pressure: Operation without retaining ring: 0.5 bar (no pressure impulses and/or vibrations); Operation with retaining ring: 1 bar (no pressure impulses and/or vibrations)
Run-in time: First start-up approx. 1 h
Material: Semipermeable membrane, PVC-U, ABS
Zero point adjustment: Not necessary

Technical features

• Model designation: CD4.2
• Measured parameter: Chlorine dioxide (ClO₂)
• Measuring ranges: multiple ranges from 0.005 ppm up to 20.00 ppm
• Detection limit: down to 0.005 mg/L (electrode-dependent)
• Resolution: 0.001 or 0.01 mg/L (range-dependent)
• Response time: ~15 seconds (T90)
• Drift: approx. -1% / month (after calibration)
• pH operating range: 1.0–12.0
• Operating temperature: 0–45 °C
• Flow cell: approx. 15–30 l/h
• Max. pressure: 0.5 bar (without retaining ring) / 1 bar (with retaining ring), no pressure impulses or vibrations
• Materials: semipermeable membrane, PVC-U, ABS
• Outputs: analog/digital options; 4-20 mA available
• Protection class options: IP65 / IP68
• Design features: galvanic isolation, low maintenance, no zero-point adjustment required