TESTO 876, Instruction Manual

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6 Using the product
27
Because of their low or non-uniform emissivity, bright metals and
metal oxides are only somewhat suited for infrared measurement.
You must anticipate highly inaccurate measurements. A remedy for
this is coatings that increase the emissivity, e.g. paint or emission
adhesive (art. no. 0554 0051) which must be applied to the object
being measured.
The following table gives typical emissivities of important materials.
These values can be used as orientation with the user-defined
settings.
Material (material temperature) Emissivity
Aluminium, bright rolled (170 °C) 0.04
Cotton (20 °C) 0.77
Concrete (25 °C) 0.93
Ice, smooth (0 °C) 0.97
Iron, emery ground (20 °C) 0.24
Iron with casting skin (100 °C) 0.80
Iron with rolling skin (20 °C) 0.77
Gypsum (20 °C) 0.90
Glass (90 °C) 0.94
Rubber, hard (23 °C) 0.94
Rubber, soft grey (23 °C) 0.89
Wood (70 °C) 0.94
Cork (20 ) 0.70
Radiator, black anodised (50 °C) 0.98
Copper, slightly tarnished (20 °C) 0.04
Copper, oxidized (130°C) 0.76
Plastics: PE, PP, PVC (20 °C) 0.94
Brass, oxidized (200°C) 0.61
Paper (20 °C) 0.97
Porcelain (20 °C) 0.92
Black paint, matt (80 °C) 0.97