Measurement Method - TESTO 831 Mode D'emploi

11. Information on infrared
measurement

11.1 Measurement method

Infrared measurement is an optical measurement
Keep lens clean.
Do not measure with clouded lens.
Keep measurement field (area between instrument and object
being measured) free of interferences: no dust and dirt
particles, no moisture (rain, steam) or gases.
Infrared measurement is a surface measurement
If there is dirt, dust, frost etc. on the surface, only the top layer will
be measured, i.e. the dirt.
In the case of shrinkwrapped foodstuffs, do not measure in air
pockets.
If values are critical, always subsequently measure using a
contact thermometer. Particularly in the food sector, the core
temperature should be measured with a penetration/immersion
thermometer.
Adaptation time
If the ambient temperature changes (change of location, e.g.
inside/outside measurement) the instrument needs an adaptation
time of 15 minutes for infrared measurement.
11.2 Measurement spot, Distance
A specific spot is determined depending on the distance from the
measuring instrument to the object being measured.
Measurement optics (Ratio Distance : Measurement spot)
testo 831
Ø 16 mm
Ø 36 mm
Ø 24 mm
Ø 18 mm
500 mm
700 mm
1000 mm
1500 mm
Ø 68 mm
Laser
Laser
2000 mm
11
Ø 100 mm