How Do Infrared Thermometers Work?
An infrared thermometer uses a built-in laser to detect the temperature of an object that is in reach or at a distance, such as an HVAC system. Here are some specific questions you should ask yourself to ensure you are choosing a high-quality infrared thermometer for your job before making this investment.
What temperature range is required?
What is the distance between the user and the object being measured (focus spot size and distance)?
Does the application require adjustable emissivity (see definition)?
Does the application require a surface/immersion probe (for user-adjustable emissivity)?
Do you need laser targeting, data hold, data logging and high/low alarms?
General Specifications for Infrared Thermometers
Here are some specifications to help you narrow down your options and choose a high-quality infrared thermometer:
Temperature Range and Resolution
Focus size and distance
accuracy
emissivity
laser aiming
data record
display type
Terms and Definitions
What is emissivity?
A measure of the ability of a surface to emit long-wave infrared radiation relative to a black body (which theoretically emits 100% or 1.0). An object's emissivity depends on its material and surface texture. For example, a given polished metal has an emissivity value of 0.20 and wood has an emissivity value of 0.95.
What is focus size and distance?
Indicates the diameter of the focal point at a given distance. For example, 1"@12" means the thermometer is focused on a circular area of diameter 12" that is 1" from the thermometer.
Convergence function The dual lasers converge to a point, and the 1-inch diameter around that point is your measurement area.
Coaxial 3-dot-laser sight shows the center and edge of the measured area, regardless of the distance from the target.
