Electrochemical chlorine sensor CL2.2

for water treatmentmonitoringfor process control

Overview
The CL2.2 free chlorine sensor, manufactured in Germany, uses a semipermeable membrane and a coated amperometric dual‑electrode system to selectively detect hypochlorous acid (HOCl). It includes integrated automatic temperature compensation, offers analog and digital signal outputs, requires no zero adjustment and exhibits pH‑dependent sensitivity. Designed for high‑salinity waters, the sensor is suitable for disinfection monitoring and process control in demanding environments, with fast response and minimal maintenance.

Special features

• Suitable for high salt concentrations (3.5–26%)
• Short response time (T90 ≈ 30 s)
• Simple handling and installation
• Made in Germany
• Short run‑in time (≈ 1 h)
• Minimal maintenance; no zero adjustment required
• Tolerates surfactants in specified variants

Applications

• Brine and seawater applications
• Pool and drinking water disinfection monitoring
• Slightly polluted process and cooling water

Ambient conditions / Installation notes

• Maintain stable pH (pH influences sensitivity and slope loss)
• Avoid surfactants where specified (no foaming agents)
• Measuring water temperature max. 45 °C (no ice crystals)
• Ambient temperature range: 0 … +55 °C
• Max. working pressure without retaining ring: up to -0.5 bar (no pressure surges/vibrations)
• Operation with retaining ring (in TARAflow FLC): up to -1 bar (no pressure surges/vibrations)
• Recommended flow rate (face velocity) in flow cell: approx. 15–30 l/h (33–66 cm/s)

Technical data

• Measurement parameter: Free chlorine (hypochlorous acid, HOCl), pH dependent
• Measuring ranges / resolution: 0.005–2.000 ppm (0.001 ppm); 0.05–20.00 ppm (0.01 ppm)
• Response time: T90 ≈ 30 s
• Measuring water temperature: 0 … +45 °C (no ice crystals)
• Ambient temperature: 0 … +55 °C
• Temperature compensation: Automatic, integrated sensor (avoid sudden temperature changes)
• Flow rate (face velocity): approx. 15–30 l/h (33–66 cm/s) in flow cell
• pH range: pH 6 – pH 8 (observe HOCl/ClO− equilibrium)
• Run‑in time: First start‑up approx. 1 h
• Zero point adjustment: Not necessary
• Max. allowed working pressure: without retaining ring: -0.5 bar; with retaining ring (TARAflow FLC): -1 bar (avoid surges/vibrations)
• Salt tolerance: 3.5% – 26% salt content
• Protection class: 5‑pole M12 plug: IP68; 2‑pole terminal with mA‑hood: IP65
• Materials: Semipermeable membrane, PVC‑U, ABS

Technical specifications

• Model: CL2.2
• Detected species: Hypochlorous acid (HOCl) — free chlorine, pH dependent
• Measuring ranges: 0.005–2.000 ppm (0.001 ppm resolution); 0.05–20.00 ppm (0.01 ppm resolution)
• Response time: T90 ≈ 30 s
• Temperature compensation: Integrated, automatic
• Measuring water temperature range: 0–45 °C
• Ambient temperature range: 0–55 °C
• Working pressure (without retaining ring): up to -0.5 bar; with retaining ring (TARAflow FLC): up to -1 bar (avoid surges/vibrations)
• Salt tolerance: 3.5%–26% salt content
• Protection class: IP68 (M12) / IP65 (2‑pole terminal)
• Materials: Semipermeable membrane, PVC‑U, ABS