Temperature Measurement - Metrel Md 9930 Benutzerhandbuch

METREL MD 9930
6.

Temperature Measurement

All objects radiate infrared energy. The amount of energy radiated is depends on the
surface temperature and the surface emissivity of the object – the higher either of
them, the higher the radiated energy. The thermal camera senses the radiated
infrared energy from the surface of the object and uses this data to calculate a
temperature. Emissivity to be used in calculation has to be set by hand.
Many common objects and materials, such as painted metal, wood, water, skin, and
cloth are very good at radiating energy (have high emissivity) and default setting of
0.95 produces accurate temperature reading.
This simplification does not work on shiny surfaces or unpainted metals as they have
an emissivity of <0.6. These materials are not good at radiating energy and are
classified as low emissivity. To measure them more accurately, an emissivity
correction is necessary. Adjusting the emissivity setting results in more accurate
temperature calculation. See Emissivity Adjustment for a list of surface emissivity
values for different materials.
Emissivity Adjustment
The correct emissivity value is an important part of temperature calculation.
Understanding the surface emissivity can help obtain more accurate temperature
measurements.
NOTE:
Reliable and consistent measurement of temperatures on surfaces with an emissivity
of <0.60 is problematic. The lower the emissivity, the higher is potential error of the
camera's temperature calculations. This is true even when adjustments to the
emissivity and reflected background are performed properly. See Settings Menu.
Material
Water
Stainless steel
Aluminum plate
Asphalt
Concrete
Cast iron
Rubber
Wood
Brick
Tape
Brass plate
Human skin
PVC plastic
Temperature Measurement
Emissivity
0.96
0.14
0.09
0.96
0.97
0.81
0.95
0.85
0.75
0.96
0.06
0.98
0.93
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