Section 8
281
MikroScan 7600PRO
Operator’s Manual
Catalog 11180-94
V15.4F 050406
Principle of Thermal Imaging
4) Comparison with blackbody surface — Option 1
A very small hole s made n the measured object to satsfy the
aforementioned blackbody conditions, and to make the tem
-
perature of the entire object uniform. Then, using the emissivity
correcting function of thermal imager, the emissivity is reduced
untl the temperature of the pont to be measured equals the tem-
perature of the small hole measured at an emssvty of 1. The
emssvty settng should be the emssvty of the object. (Ths
apples only when the condtons are the same as at measure-
ment.)
5) Comparison with blackbody surface — Option 2
If a small hole cannot be made in the object, then the emissivity
can be obtaned by applyng black pant to the object and reach-
ng a thermal equlbrum through smlar procedures. But snce
the painted object will not provide a complete blackbody, the
emissivity of the painted object needs to be set first and then
the temperature can be measured. The following figure shows
examples of blackbody pant.
8.6 Background Noise
When measuring the temperature of an object by a radiation thermometer, it is impor
-
tant to take nto consderaton the above-mentoned emssvty correcton as well as the
envronmental condtons where the measurements wll be performed.
Infrared rays enter the thermal mager from the measurng object as well as all other
objects nearby. Therefore, in order to avoid this influence, a function of environment
reflection correction, etc. is required. Also, when accurate data is required, it is necessary
to minimize the influence by shortening the transmission route of the infrared ray, for
example.
The followng methods may be useful to reduce background nose.
1) Shorten the dstance between the measured object and of the thermal
mager. Please keep a safe dstance to protect the operator as well as
the nstrument.
2) Have no high temperature object behind the measured object, such as
the sun shnng on the back of the measured object.
3) Do not allow drect sunlght to strke thermal mager.
4) Do not allow obstacles such as dust or vapor (whch attenuates the
nfrared sgnal) between the measured object and the thermal mager.
Examples of Blackbody Paint
Note:
For low temperatures, mask-
ing tape or cornstarch can be
used.
Summary of Contents for 7600PRO
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