Formaldehyde CH2O

Aeroqual designs and delivers handheld and indoor fixed air quality monitors that measure formaldehyde (CH2O).

Here we cover formaldehyde measurement principles and specifications.

Overview of formaldehyde

Formaldehyde (CH2O) is a naturally occurring compound known for its pungent, irritating odor. It is used in several industrial applications. It is often used as a precursor to more complex compounds with industrial uses. It is also used as a disinfectant to kill bacteria and fungi and is used to preserve tissues or cells for scientific analysis.

CH2O is toxic to humans and animals. Occupational exposure is mainly through inhaling the vapors. The thermal/chemical decomposition of formaldehyde-based resins or emissions from formaldehyde solutions commonly cause these vapors. It can cause headaches, difficulty breathing, and a burning sensation in the throat.


Handheld air monitors and fixed indoor monitors

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

Sensor head measurement principle

Aeroqual’s formaldehyde sensor head incorporates an electrochemical gas sensor. This sensor generates an electrical current in nA, which is proportional to the concentration of CH2O that comes in contact with the sensor. The sensor current is converted to a voltage and this voltage is used to calculate CH2O concentration.

Sensor head specifications

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

Sensor code


Sensor type


Range (ppm)


Detection limit (ppm)


Accuracy of factory calibration

<±0.05 ppm 0-0.5 ppm

<±10% 0.5-10 ppm

Display resolution (ppm)


Response time (seconds)


Formaldehyde GSE sensor cross sensitivities

Although the GSE sensor in the CH2O sensor head is designed to measure CH2O, it does show cross-interferences to other gases. The table below shows the response in ppm of the CH2O GSE sensor heads to different gases


Formaldehyde (CH2O) (SH EF)

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 formaldehyde

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

Inquire about our formaldehyde products

Our CH2O advanced monitoring systems deliver hyper-local data and real-time alerts, giving you actionable data to make the decisions that matter.