Ammonia NH3

Aeroqual designs and delivers handheld and indoor fixed air quality monitors that measure ammonia (NH3).

Here we cover ammonia measurement principles and specifications.

Overview of ammonia

Ammonia is commonly used in the agricultural industry as a fertilizer to help increase crop yield. Ammonia emissions are also a byproduct of animal waste in livestock and poultry applications. Some manufacturing processes use ammonia, such as in the production of plastics, textiles, and pesticides, as well as in the fermentation industry and as an antimicrobial agent. It is also found in many household and industrial strength cleaning products.

Ammonia is a toxic gas that can cause burning in the respiratory tract when inhaled. Those most at risk of excess inhalation are workers whose industries use ammonia.


Handheld air monitors and fixed indoor monitors

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

Ammonia sensor head measurement principle

Aeroqual offers two different sensor types for ammonia measurement in our sensor head range: the Gas Sensitive Semiconductor (GSS) sensor and the Gas Sensitive Electrochemical (GSE) sensor.

The GSE sensor head incorporates an electrochemical gas sensor. This sensor generates an electrical current in nA, which is proportional to the concentration of NH3 that comes in contact with the sensor. The sensor current is converted to a voltage and this voltage is used to calculate NH3 concentration.

The GSS sensor head incorporates a semiconducting gas sensor, which is manufactured by Aeroqual. The sensing layer is a p-type semiconductor whose resistance increases when NH3 gas is present. The change in sensor resistance is used to calculate NH3 concentrations.

Ammonia sensor head specifications

The table below contains the ammonia sensor head specifications. These can be used on our Ranger, S Series and Series 900 products. Both ranges are designed for industrial health and safety.

Sensor code



Sensor type



Range (ppm)



Detection limit (ppm)



Accuracy of factory calibration

<±5 ppm + 15%

<±0.5 ppm + 10%

Display resolution (ppm)



Response time (seconds)



Ammonia GSE sensor head cross sensitivities

Although the GSE sensor in the ammonia sensor head is designed to measure NH3, it does show cross-interferences to other gases. The table below shows the response in ppm of the NH3 GSE sensor heads to different gases.


Ammonia (NH3) (SH ENG)

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 ammonia

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

Inquire about our ammonia products

Our NH3 advanced monitoring systems deliver hyper-local data and real-time alerts, giving you actionable data to make the decisions that matter.