Free Chlorine Analyzer Reagentless FX-CL-F

Simplified Free Chlorine Monitoring and Control



What It Does For You

Our amperometric chlorine sensor with reduced pH dependence gives you reliable readings without the need for pH adjustment or compensation in most cases.

Lower your operating cost with no reagents, buffer solutions or pH sensors with associated maintenance as well as need for service contracts since maintenance is  infrequent and easy to perform.

Membrane Covered Sensor Options

Optional 2-electrode sensor for up to 7pH.

Our standard 3-electrode potentiostatic sensor for up to 8.5pH reduces pH effects and provides more stability and less drifting.

Both sensors measure the hypochlorous acid portion of free chlorine and have integral temperature compensation.


No Zero Cal

No zero point calibration is required; just analyze a grab sample to calibrate your span.

High Range Capability

Food processing operations are often required to maintain high chlorine residual concentrations to ensure disinfection.

For high range applications we offer 0.05-50, 100 or 200 mg/l (ppm) measuring ranges.

Standard ranges are : 0.05 - 0.50 up to 0.05 - 20 mg/l (ppm)


  • Distribution system monitoring and boosting
  • Drinking water disinfection monitoring and control
  • Produce washing
  • Cooling water Legionella control


Flow Cell

This type of sensor cannot be simply be submerged into a tank, wet well or pipe.

It can only be used in a flow cell in which pressure and flow rate is controlled and consistent.

Since chlorine is consumed at the electrode it's supply must be continually replaced at a minimum flow rate.

Excessive or fluctuating pressure can rupture the membrane.

Sample Recycling

Since no reagents are added to the measuring cell, locations without a drain can return the sample to the process if regulations allow.


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Standard Features

The model FX-CLF is virtually plug and play,  pre-mounted with flow controls on a 12" x 24" PVC panel for quick and easy installation.

  • A single 4-20mA output auto scaled to the sensor operating range. Temperature measurement and output is optional.
  • Programmable high and low 1A SPDT alarm relays have an adjustable delay up to 5 minutes.
  • Intuitive glass touch screen display and interface is similar in appearance and function to your smart phone.
  • No flow alarm and data logging is optional
  • Water resistant IP67/NEMA 4x Polycarbonate enclosure with UV stabilized clear door to protect the touchscreen.
  • Microprocessor based 24VDC electronics using 88-264 VAC 50/60 Hz input via supplied 2-meter power cord.

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Battery Power & Remote Sites

Low maintenance and power consumption make the analyzer ideal for remote unmanned well sites or booster stations.

The analyzer is capable of being battery powered since the electronics consume less than 3 watts. Please contact the factory for details.

The sensor can tolerate zero chlorine for up to 24 hours. This allows the analyzer to used at sites that only operate several hours per day provided the sensor stays wet and you allow a re-acclimation time upon re-starting.

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Water Quality

Sensors are ideally for use in water of drinking or pool quality with no suspended solids. Water treated to USEPA Primary and Secondary Drinking Water Standards is recommended.

Corrosion inhibitors and tensides from cleaning agents will damage the membrane properties and must be avoided.

Operating in poorer quality water may be possible but will likely require more frequent cleaning and electrolyte replacement, which can defeat the low maintenance purpose of this technology. This applies to all membrane covered chlorine sensors.

Elevated levels of iron will prevent the 3-electrode sensor from producing an output signal, while the 2-electrode sensor is unaffected.

See our bare electrode model FX-CLv2 if your water doesn't meet these standards, or for wastewater.

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