General Precautions for Infrared Temperature Sensors

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Emissivity (ε)

The infrared energy emitted from the measurement target has a specific emissivity according to its composition and surface finish.
The emissivity of a material becomes closer to 1.0 for substances which readily emit infrared radiation (surfaces that are not glossy and reflective), whereas it becomes closer to 0 for materials that do not readily emit infrared (such as the polished surfaces of metals).
For normal applications, the standard emissivity of 0.95 can be used. When improved accuracy of temperature measurement is needed, however, the emissivity should be accordingly coordinated.

Field of View (FOV)

All the measurement targets need to be measured at a distance in which the target object image size equals or exceeds the FOV. When the target object size is larger than the FOV, the temperature can be immediately measured, regardless of the distance. The condition in which the measurement target is too small to satisfy the FOV conditions is sometimes referred to as “FOV chipping,” which does not allow accurate temperature measurement because it could also include measurements of non-target areas.

Detection surface

Dirt, dust or flaws on the detection window may affect normal operation.
Lightly wipe off dirt using a dry cloth. Do not use organic solvents such as paint thinner.

Effects of Water Vapor

A large amount of moisture in the air between the measurement target and the sensor may absorb infrared rays, resulting in a measured temperature lower than actual.

Metal measurement

Shiny or polished metals are generally difficult to measure due to their low emissivity. In this case, using black tape or paint spray allows measurement.

Measurement through glass

Normally quartz glass becomes more opaque as the infrared wavelength becomes longer with a larger emission (absorption). Temperature measurement through glass is therefore not available because in this case it measures the temperature of the glass surface.

Environmental temperature change

Abrupt change in the ambient temperature (Ta) causes measurement errors. Avoid abrupt temperature change.

Usage environment

Avoid use or storage of the sensors in a place exposed to; splashes of chemicals or corrosive gasses, abrupt temperature changes, direct sun, vibrations, or impacts.
Dew condensation or freezing may also influence performance.