InfRec Thermo Gear G100, Operation Manual

Page: 131 / 141

Chapter 7 Appendix
5) Comparison with blackbody surface
If a small hole cannot be made in the object, then the emissivity can be obtained by applying
black paint to the object and reaching a thermal equilibrium through similar procedures. But
since the painted object will not provide a complete blackbody, first set the emissivity of the
painted object and then measure the temperature. Following Fig. 6.1 shows examples of
blackbody paint.
95691-2935-0000
CAUTION
Item name Manufacturer Emissivity Measuring wavelength
Heat-resistant paint (black) Asahi Pen 0.98 8 to 13 [ μ m]
Heat-resistant paint (black) Asahi Pen 0.95 3 to 5.3 [ μ m]
Niflon tape Nitto Denko 0.94 8 to 13 [ μ m]
Table. 7.1 Example of Blackbody Paint
· As the heat-resistive paint (black) contains an organic solvent, please follow the operation
manual of the manufacturer for the handling.
Comment s
)
· Measuring wavelength of G100/G120 series is 8 to 14 [ μ m].
7.1.4 Background noise
What to be careful in measuring a temperature of an object by a radiation thermometer is not
only above mentioned emissivity correction but also measuring environment conditions.
Infrared rays enter into the Thermo Tracer from not only measuring object but also the other.
Therefore, in order to avoid from this influence, function of environment reflection correction,
etc. is required. Also, when an accurate data is required, it is necessary to minimize the
influence such as shortening the transmission route of infrared day.
Following methods may be considered to remove the background noise.
(1) To shorten distance between a measuring object and the incident window of the Thermo
Tracer as much as possible. However it is necessary to keep safety distance for
measuring person.
(2) To be no high temperature object behind the measuring object.
Examples,
· No high temperature object such as the sun exists behind.
· Change position of measuring person within safety range.
(3) Not to get direct sunlight in the Thermo Tracer.
(4) Not to put obstacles such as dust or vapor which attenuates infrared radiation (signal)
between the measuring object and the incident window of the Thermo Tracer.
8 - 6