Sonel KT-160, Инструкция по эксплуатации

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KT-160 USER MANUAL 95
4 Precise temperature measurement
Temperature measurement accuracy depends on many factors, among others: emissivity,
background temperature, the distance from the object, relative humidity. During the
measurements the camera makes the correction based on signals read from the sensors.
For some situations and materials it may be necessary to manually adjust the
parameters.
Emissivity. Infra-red measurements base on receiving the infra-red radiation emitted by
objects. The amount of radiation energy is based on two main factors: surface
temperature and emissivity of the object's surface. Default emissivity is 0.98 and it applies
to most surfaces.
The values of emissivity for some materials are given in the Emissivity Table (Section 8).
Poorly chosen value of the emissivity factor may cause significant reading errors for the
temperature, therefore KT-160 and KT-160A cameras allow the user to choose the
emissivity factor within the range of 0.01 ... 1.00 (see chap. 3.8.1).
Measurement accuracy also depends on the ambient temperature. The default
temperature is the temperature measured by the camera and this value may be changed
manually to compare and establish a proper relation between measured object's
temperature and certain types of the ambient temperature (e.g., sky, snow).
Adjustment of the ambient temperature is described in Chapter 3.8.2.
The influence of the distance from the object on the measurement accuracy may be
significant, depending on the medium in which the object is located (air, fog, smoke ...)
and its impact on the attenuation of thermal radiation. It is possible to adjust the default
value (1.8 m) in the range of 0.1 ... 10m (30m when using telephoto lens). The method of
the distance adjustment is described in chapter 3.8.4.
Relative humidity may also influence the accuracy of measurement, it is possible to
change the default value (70%) for a value from the range of 0 .. 100% (the function
described in section 3.8.5).
In addition, in order to get an accurate temperature reading, the user must hold the
camera steady and set the focus very well (Section 3.2).