InfRec Thermo Gear G100, Руководство по эксплуатации

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Chapter 7 Appendix
cannot be measured. In other words, a variation or change in emissivity will cause a change in
the indications on the Thermo Gear.
To approach the true temperature therefore,
(1)The emissivity must approximate 1. ( → The measured object must be nearly a blackbody.)
(2)The emissivity must be corrected. ( → The emissivity of the measured object must
approximate to 1 by way of calculation.)
Therefore, in order to perform correct measurement for true temperature, the emissivity is
determined as follows,
1) Check by way of literature
Various literature carries a physical constants list, but if the measuring condition at that time is
not satisfied, the constants will not be usable. In such case the literature should be used only for
reference.
2) Determination by ratio (1)
Confirm that the measured object in thermal equilibrium and the blackbody-type source is at the
same temperature by using a contact-type thermometer. Then measure the object and the
blackbody-type source with the radiation thermometer, and the energy ratio at that time will give
the emissivity.
EK : ES = 1 : X
…..
(5)
EK : energy of blackbody-type source
ES: energy of measured object
X: emissivity of measured object
*Indicated here is the ratio, not the temperature.
3) Determination by ratio (2)
Attach an object resembling a blackbody (blackbody part) to a heater, unify the temperatures of
the measuring object and the blackbody part, and obtain the ratio of infrared radiation energies
at that time. [* Same as in 2) above]
4) Comparison with blackbody surface
Make a very small hole in the measured object to satisfy the aforementioned blackbody
conditions, and make the temperature of the entire object uniform. Then, using the emissivity
correcting function of Thermo Gear, reduce the emissivity until the temperature of the point to
be measured equals the temperature of the small hole measured at an emissivity of 1.The
emissivity setting should be the emissivity of the object. (This applies only when the conditions
are the same as at measurement.)
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