Ammonia Gas Detection

Selecting the Proper Ammonia Gas Detector: Ammonia gas detectors come with varying features, sensor elements, and ranges. Below we will discuss what to look for when selecting the proper ammonia gas detector for different applications.

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Ammonia Gas Detector Selection Guide

When choosing an ammonia detector, there are certain features that mesh well with the food industry. CTI has designed these features into all of our gas detectors, and when they work in the food industry, they work almost anywhere else. Specifically with facilities using Ammonia, the environments are exceptionally tough and nasty. A gas detector that will thrive in the food industry must be designed to survive the harshest of conditions.

CTI has developed features to fight again moisture, heat, extreme cold, washdown sprays, blast freezers, and outdoor environments. Below is a list of features incorporated into CTI gas detectors that allow them to succeed in the harshest environments for years of exceptional use:

CTI Ammonia Gas Detector Features:

  • On Board heaters
  • Potted Circuit Boards
  • Corrosion resistant components and enclosures
  • UV resistant materials
  • Humidity and temperature sensors to fight extreme climate swings.
  • Pre-Calibrated Smart Cell sensor elements for quick and easy replacement.


CTI Ammonia Detectors are industrial strength and designed for:

Engine Rooms

Cold Storage



Blast Freezers

Food-Processing areas




fishing vessels

ventilation ducts

Tank rooms

chemical plants

...and more!

Ammonia Gas Detector Models

Among a host of shared features, CTI offers different models of ammonia gas detectors for different needs. Below is a table highlighting key differences between models.



Locating Ammonia Detectors

Locate ammonia detectors within 30-45ft of a potential leak source. This leak source could be compressors, evaporators, pent houses, blast freezers and others. For rooms containing 1 sensor, locate the sensor in the breathing zone (~5ft off the floor) for optimum personnel protection. For rooms requiring multiple detectors, a 2nd detector can also be placed in the breathing zone, or placed up high with attention paid to maintenance access.

Ammonia vapor is lighter than air; however, a liquid leak will start from the ground up, and most cold storage facilities have ventilation that mixes the air content in each room adequately for detectors being placed in the breathing zone for vapor leaks.

Ammonia Detection in Compressor Rooms

For compressor rooms, sensor redundancy is recommended due to the catastrophic leak potential of the compressors. Audio-Visual indication inside the room, and outside of each entrance shall take place at 25 ppm NH3, emergency ventilation at 150 ppm, and compressor shutdown at less than 40,000 ppm (10,000-20,000 is industry standard) per code. To satisfy these requirements, 2 low level sensors (0-250 ppm is standard), and 1 high level sensor (0-2% is standard) are recommended for compressor rooms. The 2 low level sensors should be located on either side of the engine room, close to leak sources. The 0-2% sensor should be located centrally, accounting for the emergency exhaust intake.

Ammonia Detection in Vent Lines

Vent line detectors should be located 3-5 feet above the roof line in the relief header. The GASMARK MV includes a mounting kit to attach to the pipe. A vent line release will be pure ammonia, and the sensor should be set to alarm at 5,000-10,000 ppm ammonia. Alarm setpoints less than 5,000 ppm can false alarms due to the rough conditions on the roof, or other gases in the vicinity.

Ammonia Detection in Refrigerated Spaces

Ammonia detectors located in refrigerated spaces should alarm to a monitored location and activate audio-visual alarms at 25 ppm, in addition to closing solenoids or triggering other desired outputs. The standard range to accommodate the lower detection levels is 0-100 ppm. Sensor element ranges up to 0-300 ppm can be used for these applications as well. Sensors should be located in the breathing zone within 30-45 feet of a potential leak source for optimum personnel protection.

Alarm Levels and Recommended Outputs

See below table for ammonia detection alarm levels and outputs. For a thorough guide of codes and design specifications pertaining to Ammonia, see our Ammonia Codes and Design Specifications Page.


Ammonia Sensor Elements

CTI offers 2 different types of ammonia sensor elements. These NH3 sensor elements are found in the new GASMARK line, as well as the prior generation GG line of detectors. All CTI NH3 sensor elements are designed to be ammonia specific and eliminate false alarms from off-gassing and other environmental factors.

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Electrochemical sensors for ammonia detection are ideal for most applications requiring sensitivity to levels less than 1000 ppm. They offer limited cross sensitivity issues, relatively quick response to ammonia, and good sensor life. CTI’s electrochemical ammonia sensor elements are designed to greatly reduce ill effects caused by temperature and humidity swings that cause nuisance alarms. The accuracy at lower levels makes the electrochemical sensor an outstanding choice for personnel protection throughout most facilities.

Catalytic Bead

Catalytic Bead sensors for ammonia detection are designed for high level leak detection to prevent catastrophic events. These sensors are used in engine rooms for shutdown, and vent line sensors. The catalytic bead sensor element offers quick response and accuracy at higher levels, but cannot detect reliably below 1000 ppm. Catalytic bead sensors have long life and very limited cross sensitivity issues due to the high range.





Frequently Asked Questions

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Ammonia Gas Detectors are an integral part of a complete gas detection system.

For more information about designing a complete system see the How it Works page.To contact CTI with a quote request please use the below link, or contact CTI via phone or email.