EN
ST-8810
Measurement considerations
23
Reminders
• The thermometer is not recommended for measuring shiny or polished
metal surfaces such as stainless steel, aluminium, etc. (see chapter
“Emissivity” on page 23).
• The thermometer cannot measure through transparent surfaces such as
glass. It will measure the surface temperature of the glass instead.
• Steam, dust, smoke, etc., can prevent accurate measurement by
obstructing the thermometer’s optics.
Emissivity
Most organic materials and painted or oxidized surfaces (90 % of typical
applications) have an emissivity of 0.95 (pre-set in the unit). Inaccurate read-
ings will result from measuring shiny or polished metal surfaces. To compen-
sate cover the surface to be measured with masking tape or flat black paint.
Allow some time for the tape to reach the same temperature as the material
underneath it. Measure the temperature of the tape or painted surface.
Emissivity values
Substance
Thermal
emissivity
Substance
Thermal
emissivity
Asphalt
0.90 to 0.98
Cloth (black)
0.98
Concrete
0.94
Human skin
0.98
Cement
0.96
Lather
0.75 to 0.80
Sand
0.90
Charcoal (powder)
0.96
Earth
0.92 to 0.96
Lacquer
0.80 to 0.95
Water
0.92 to 0.96
Lacquer (matt)
0.97
Ice
0.96 to 0.98
Rubber (black)
0.94
Snow
0.83
Plastic
0.85 to 0.95
Glass
0.90 to 0.95
Timber
0.90
Ceramic
0.90 to 0.94
Paper
0.70 to 0.94
Marble
0.94
Chromium oxides
0.81
Plaster
0.80 to 0.90
Copper oxides
0.78
Mortar
0.89 to 0.91
Iron oxides
0.78 to 0.82
Brick
0.93 to 0.96
Textiles
0.90
WaecoST-8810_OPM_4445103143_EMEA10_2020-08_06.book Seite 23 Donnerstag, 20. August 2020 7:19 19
