How do infrared thermometers work?
An infrared thermometer uses a built-in laser to detect the temperature of an object that is out of reach or at a distance, for example an HVAC system. Here are some specific questions you should ask yourself to ensure you pick a high quality infrared thermometer for the job before you make that investment.
- What temperature range is required?
- What distance will the user be from the object(s) being tested (Focus Spot Size and Distance)?
- Do application(s) require adjustable emissivity (see definitions)?
- Do application(s) require a surface/immersion probe (for user adjustments to emissivity)?
- Do you require laser sighting, data hold, data logging, and high/low alarm?
Common Specifications of an Infrared Thermometer
Here are some specifications that can help you narrow down your choices and choose a high quality infrared thermometer:
- Temperature Range and Resolution
- Focus Spot Size and Distance
- Laser Sighting
- Data Logging
- Display Type
Terms and Definitions
What is Emissivity?
The measure of a surface's ability to emit long-wave infrared radiation, relative to a black body (which theoretically emits at 100% or 1.0). The emissivity of an object depends upon its material and surface texture. For example, a given polished metal may have an emissivity value of 0.20 and wood a value of 0.95.
What is Focus Spot Size And Distance?
Indicates the diameter of the focal point at a given distance. For example, 1" @ 12" indicates that a thermometer focuses on a 1" diameter circular area 12" away from the thermometer.
Convergence Feature dual lasers which converge to a single point, a 1" diameter around that point is your measurement area.
Coaxial 3 Dot - Laser sighting shows both center and edge of area being measured regardless of the distance from target.