testo 830-T1 Bedienungsanleitung Seite 14

14 11. Information on infrared measurement
Apply emissivity enhancing layers such as varnish or emission
adhesive tape (Item no. 0554 0051) to the object being
measured. If this is not possible, measure with the contact
thermometer.
Emissivity table of the most important materials
(typical values)
Material (Temperature)
Aluminium, bright-rolled (170°C/338°F) 0.04
Cotton (20°C/68°F)
Concrete (25°C/77°F)
Ice, smooth (0°C/32°F)
Iron, polished (20°C/68°F)
Iron with cast skin (100°C/212°F)
Iron with rolled skin (20°C/68°F)
Plaster (20°C/68°F)
Glass (90°C/194°F)
Rubber, hard (23°C/73°F)
Rubber, soft grey (23°C/73°F)
Wood (70°C/158°F)
Cork (20°C/68°F)
11.3 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 830-T1
testo 830-T2
Ø 16 mm
Ø 16 mm
Ø 66 mm
500 mm
1000 mm
Ø 58 mm
500 mm
1000 mm
ε
Material (Temperature)
Heat sink, black anodised (50°C/122°F) 0.98
0.77 Copper, lightly tarnished (20°C/68°F)
0.93 Copper, oxidised (130°C/266°F)
0.97 Plastics: PE, PP, PVC (20°C/68°F)
0.24 Brass, oxidised (200°C/392°F)
0.80 Paper (20°C/68°F)
0.77 Porcelain (20°C/68°F)
0.90 Black paint, matt (80°C/176°F)
0.94 Steel,
heat-treated surface (200°C/392°F)
0.94
Steel, oxidised (200°C/392°F)
0.89
Clay, fired (70°C/158°F)
0.94
Transformer paint (70°C/158°F)
0.70
Brick, mortar, plaster (20°C/68°F)
Ø 116 mm
2000 mm
5000 mm
Ø 100 mm
2000 mm
5000 mm
Ø 216 mm
laser
laser
Ø 183 mm
laser
ε
0.04
0.76
0.94
0.61
0.97
0.92
0.97
0.52
0.79
0.91
0.94
0.93
Ø 516 mm
Ø 433 mm