Refrigerant Leak Detectors

Refrigerant Leak Detectors

Refrigerant Leak Detectors are available to pinpoint specific leaks and also to monitor areas or rooms. Monitors are important to check the level of refrigerant in an enclosed room with one or more refrigerant equipment. These instruments use a variety of methods to find leaks. Common methods today include infrared, UV, heated diode, and corona discharge.

Refrigerant Leak Detector Selection Criteria

• Sensitivity
• Detection Limit
• Selectivity of Refrigerants

Both heated diode and corona discharge (while technically different) operate in a similar fashion because they both use two electrodes in their sensors. These determine leaks based on refrigerant concentration or current drop between the two electrodes. UV leak detectors require that a special dye be circulated throughout the system that only the UV detector can see. Anywhere this dye is visible outside the system, there is a leak. IR leak detectors on the other hand are entirely different.


How Do IR Refrigerant Leak Detectors Work?

Infrared (or IR) sensors work on the principle that refrigerants reflect a certain spectrum of light that is “below red” or infrared.  When refrigerant is drawn into the sensor, it travels between a light/heat source and a sensor that is constantly receiving a “picture” of that light. Like a cloud that reflects solar radiation and “blocks” out the sun, the refrigerant reflects the infrared radiation and blocks the sensor from receiving the complete picture.  The result is a trigger.  However, after the “picture” stays the same for a while, the sensor no longer senses a change and the triggering stops.

IR sensors act almost exactly like the motion sensors that trigger lights outside.  The outside sensors are taking a picture of a designated area.  When someone walks into that picture a change is detected.  The light turns on.  If you stand in the same place without moving, eventually the light turns off until you move again.

Because of this unique sensor, IR detectors that sense change are used differently from the more commonly used heated element detectors. You have to use a double-pass or sweeping motion to pinpoint a leak, meaning when you pass the detector by a refrigerant leak, it blocks out light to the sensor, and an alarm triggers.  Next you sweep back and it triggers again. The midpoint is the source of the leak. 

IR Advantages

• Essentially reacts to all refrigerants the same way, meaning it triggers on R-507 the same way it does on R-22
• Triggers on all CFCs, HFCs, HCFCs and blends
• Doesn't trigger on oil or moisture like other types of detectors
• By far are the longest-lasting leak detection sensors on the HVAC market today
• Sealed sensor - Unlike heated diode and corona discharge leak detectors, the sensor doesn't "touch" refrigerant as it passes through the instrument. Heated diode and corona discharge units tend to degrade or fail when they come in contact with high concentrations of refrigerants or liquids.
• Senses change in refrigerant levels
• Works even in contaminated environments
• Up and running in less than 30 seconds. Some heated elements and corona discharge units take much longer to warm up. UV dyes can take several hours to travel through a running system and can degrade system components.