Carbon Dioxide Detectors

Ammonia and hydrocarbons are commonly used as refrigerants in food processing and cold storage facilities. In recent years, however, carbon dioxide has gained tremendous popularity as an industrial refrigerant. Unfortunately, with this trend comes a plethora of serious safety risks. Thankfully, our CTI team proudly carries industry-leading carbon dioxide detectors for your industrial CO2 monitoring systems and other commercial applications. Carbon dioxide gas detectors from CTI have different sensor element types and ranges. The information below will assist in choosing the correct configuration for your facility to ensure that you are in compliance with all safety standards. Or contact our friendly team today to learn more about our carbon dioxide detectors.

Shop CO2 Detectors

CO2 Compressor Mericle


CTI Ammonia Detectors are industrial strength and designed for:

dry ice plants

Dry Ice Plants


CO2 freeze hoods

Cold Storage

Indoor Air Quality

Chemical Plants

Regulatory Concentrations of Interest

There are several CO2 thresholds to consider

OSHA Permissible Exposure Limit (PEL):

        • 5,000ppm TWA (8 hour time weighted average)

NIOSH (National Institute for Occupational Safety and Health) Recommended Exposure Limit:

        • 5,000 ppm TWA
        • 30,000 ppm STEL (Short Term Exposure Limit = 15 minute time weighted average)
        • 40,000 ppm IDLH (Immediately Dangerous to Life and Health)

ACGIH (American Conference of Governmental Industrial Hygienists) TLV (Threshold Limit Value):

        • 5,000 ppm TWA
        • 30,000 ppm STEL

How to Buy A CO2 Detector

Codes and Specifications

CTI engineers have carefully studied the latest regulatory standards for the industrial use of CO2 and compiled the information into a helpful CO2 detection design guide. Download your free copy here.”

The ABC’s of CO2 Detection

Alarm Levels and Recommended Outputs

See below table for CO2 detection alarm levels and outputs. For a thorough guide of codes and design specifications pertaining to Carbon Dioxide. see our “ABC’s of CO2” Guide.

Use Set Point Action
As a refrigerant or in a process 0.5% (5,000 ppm) Investigate potential leak with hand-held CO2 leak detector

Initiate ventilation

As a refrigerant 1.0% (10,000 ppm) Shut down valves to evaporator

Activate audio visual alarms and evacuate the room.

In a process 3.0% (30,000 ppm) Activate audio visual alarms and evacuate the room.

CTI Carbon Dioxide Detectors are built for harsh conditions and designed to prevent false alarms:


    • Built-in, automatic heaters to withstand temperatures down to -50F.



    • NDIR infrared sensor element with Carbon Dioxide specific technology.



    • Sensor element ranges designed to accurately monitor OSHA’s TWA, PEL and STEL setpoints for personnel protection.



    • Corrosion, weather, and chemical resistant NEMA 4X detectors offered in either polycarbonate or stainless steel enclosures.


Carbon Dioxide Detection for CO2 Cascade Systems

When Carbon Dioxide is used with Ammonia in a CO2 Cascade system, CO2 detectors are required in the compressor room as well as in the refrigerated and process areas. CO2 sensors should be located in the breathing zone near leak sources, such as compressors and evaporators. CO2 is always present in air, and concentrations can build up to alarm levels without a leak from the refrigeration system. If possible, in addition to accounting for leaks, locate sensors near high traffic areas to account for general CO2 build up. The 0-3% range is ideal for cascade systems, offering detection at the TWA (0.5%) and the STEL (3%).

Carbon Dioxide Detection for Bottling Plants

Bottling plants and other facilities using CO2 in a process should use a 0-3% range detector to initiate ventilation at the TWA(0.5%) and evacuate at the STEL(3.0%). Sensors should be placed at or below the breathing zone, near where operators work, and/or where people frequent for personnel protection. Sensors located at the source can cause inflated readings compared to what personnel are experiencing in their working environment. Sensors should only be located at the leak source if personnel are frequently present.

Carbon Dioxide Detection for Wineries

Wineries can have elevated CO2 levels during the fermentation process. Care should be taken to protect personnel from dangerous levels in these areas. A 0-1% sensor range is ideal for wineries to monitor the lower levels that are often found. The 0-1% range can closely monitor at and below the TWA, and up to 1% CO2 where ventilation can be activated to maintain a safe environment. Sensors should be located at or below the breathing zone, where personnel are most likely to be exposed.

Carbon Dioxide Sensor Elements

Carbon Dioxide sensor elements from CTI are offered with an infrared sensor element in different ranges and packages. The Infrared sensor elements boast long sensor life and carbon dioxide specific sensing technology. Rapid response times and long lasting accuracy make the infrared sensor element a great choice. Constant target gas exposure and background gases are not an issue for the infrared sensing element. Infrared sensors are only offered in higher ranges, which meshes well for CO2 detection at levels concerning personnel protection. Proper maintenance should take place to maintain the low end of the range, by calibrating the active zero with 500 ppm CO2 to maintain accuracy at everyday levels.

Carbon Dioxide DETECTORS

GG-CO2 Polycarbonate

GG-CO2 Stainless

GG-CO2 Carbon Dioxide Detector

Portable CO2 Detector

Frequently Asked Questions

Choose CTI

Carbon Dioxide 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.