Chlorine Cl2

Aeroqual designs and delivers handheld and indoor fixed air quality monitors that measure chlorine (Cl2).

Here we cover chlorine measurement principles and specifications.

Overview of chlorine

Chlorine (Cl2) is a toxic gas that plays an important role in water sanitation as it can kill bacteria and other microbes present in water. Other industrial processes that use chlorine include production of plastics, textiles, antiseptics, and household cleaning products, and in solvents for dry cleaning and metal degreasing.

Exposure to high levels of chlorine gas can cause coughing and chest pain, respiratory irritation, and damage.

Aeroqual offers a portable or fixed solution for chlorine gas detection. We do not offer sensors capable of measuring chlorine concentrations in water.


Handheld air monitors and fixed indoor monitors

The chlorine sensor head features in our handheld air quality monitors: Ranger and S Series, and indoor fixed monitor range Series 900.

Chlorine sensor head measurement principle

Aeroqual’s chlorine sensor head incorporates an electrochemical gas sensor. This sensor generates an electrical current in nA, which is proportional to the concentration of Cl2 that comes in contact with the sensor. The sensor current is converted to a voltage and this voltage is used to calculate Cl2 concentration.

Chlorine sensor head specifications

The table below contains the chlorine sensor head specifications. It can be used on our Ranger, S Series and Series 900 products, for outdoor environmental monitoring or industrial health and safety.

Sensor code


Sensor type


Range (ppm)


Detection limit (ppm)


Accuracy of factory calibration

<±0.02 ppm + 10%

Display resolution (ppm)


Response time (seconds)


Chlorine GSE sensor cross sensitivities

Although the GSE sensor in the Cl2 sensor head is designed to measure Cl2, it does show cross-interferences to other gases. The table below shows the response in ppm of the Cl2 GSE sensor heads to different gases.


Chlorine (Cl2) (SH ECL)

O3 1 ppm


CO 25 ppm


NO2 1 ppm


SO2 1 ppm


H2S 1 ppm


Ethylene 5 ppm


CO2 400 ppm


H2 1 ppm


NO 5 ppm


Products that measure chlorine

The following products measure chlorine, as well as particulate matter and gaseous pollutants in real-time.

Inquire about our chlorine products

Our Cl2 advanced monitoring systems deliver hyper-local data and real-time alerts, giving you actionable data to make the decisions that matter.