Targeted Chlorine Protection for Harsh Industrial Environments

Alphasense chlorine (Cl2) gas sensors provide reliable toxic gas monitoring for industrial safety, wastewater treatment, and emergency response applications. Designed around proven electrochemical platforms, the portfolio supports portable instruments, fixed installations, and miniature personal monitors operating in demanding temperature and humidity conditions.

Sensor Product Overview


Portable & Industrial Safety – A Series Cl2 Sensors


  • CL2-A1 – A-Series PPM chlorine sensor for handheld and portable detectors in general and industrial safety. 0–20 ppm range.

Fixed & High Humidity Installations – B Series Cl2 Sensors


  • CL2-B1 – B-Series chlorine sensor for fixed systems and high-humidity environments.

Miniature & Wearable – D and H Series Cl2 Sensors


  • CL2-D4 – Miniature D Series Cl2 sensor for clip on personal monitors and compact handhelds.
  • CL2-H4 – Ultra-low-profile H-Series sensor for clipped and wearable devices where height is constrained.

Integrated Smart Technology (IST) Cl2 Versions


  • CL2-A1-IST | CL2-B1-IST add on-sensor memory and temperature measurement for plug-and-play integration and simplified temperature compensation

Choosing the Right Cl2 Sensor by Application


Portable / Personal Safety


  • CL2-A1 – General industrial safety and emergency response in handheld and transportable detectors.
  • CL2-D4 | CL2-H4 – Clip-on and wearable monitors where footprint and height must be minimized.

Fixed Systems & High-Humidity Environments


  • CL2-B1 – Fixed gas detection in water treatment plants, chemical facilities, and other wet or outdoor environments where larger B-Series electrolyte volume supports stability.

Key Benefits Across the Cl2 Sensor Portfolio


  • Multiple mechanical formats (A, B, D, H) for portable, wearable, and fixed systems.
  • PPM-range detection tailored to worker safety and emergency response thresholds.
  • IST “+” options with temperature sensing and on-sensor memory for plug-and-play
  • Stable operation over wide temperature and humidity ranges for real-world plant conditions.

Why OEMs Choose Alphasense


OEMs designing Cl2 monitors select Alphasense for:

  • A consistent A/B/D/H format strategy that aligns with existing multi-gas architectures.
  • Shared electrochemical and IST technology platforms across multiple toxic gas families, simplifying electronics and certification.
  • Extensive performance characterization and application support for industrial safety and environmental monitoring.

How Cl2 Sensors Work


Alphasense Cl2 sensors use electrochemical amperometric technology:

  • A controlled reaction at the working electrode converts chlorine concentration into an electrical current.
  • A reference electrode holds the correct bias, while the counter electrode balances the reaction.
  • Front-end electronics (AFE / ISB or OEM circuitry) read the current and apply calibration data, converting it into a Cl2 reading. IST variants add on-board memory and a temperature IC so that calibration data and compensation parameters travel with each sensor.

Why Measure Chlorine Gas


Chlorine is a toxic, corrosive oxidizer widely used in water treatment, chemical production, and disinfection processes. Acute exposure can cause severe respiratory irritation and lung injury, while uncontrolled leaks drive corrosion and equipment damage. Continuous Cl2 monitoring helps:

  • Protect workers in water treatment plants, chemical facilities, and storage areas.
  • Provide fast alarm signalling in confined spaces and emergency response scenarios.

Select Cl2 Sensor

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