Distance And Measuring Spot Size; Emission Factor - Trotec TP4 Manuel D'utilisation

The TP4 has a dual laser, which automatically displays the size
of the measurement spot. The distance between the two laser
beams corresponds to the diameter of the measuring spot.
12.5 mm spot
@ 150 mm
To deactivate this, press the laser On/Off button
The laser symbol goes out.
For measurements in the darkness the background illumina -
tion can be activated and deactivated with the background il-
lumination button .
The active background illumination is displayed by the
symbol (TP8 only).

8. Distance and measuring spot size

(Distance-to-spot-ratio D:S)
To achieve accurate measuring results the target must be larger
than the measuring spot of the infrared thermometer. The de-
termined temperature is the average temperature of
the measured surface. The smaller the target the shorter the
distance from the infrared thermometer must be. The exact
measuring spot size can be taken from the diagram
All manuals and user guides at all-guides.com
T P 4
again.
.
Operating manual – English
This is also printed on the instrument. For accurate measure-
ments, the target must be at least twice as big as the measur-
ing spot. The focal point of the TP8 is 914 mm.

9. Emission factor

The emission factor is a value used to describe the energy ra-
diation characteristic of a material. The higher this value, the
higher the capacity of the material to emit its own thermal radi-
ation, without the influence of reflections.
Metal surfaces or glossy materials have a low emission factor
and therefore give inaccurate measured values. Please take
this into account when using the infrared thermometer.
For compensation the surface of glossy parts can be covered
by matt adhesive tape or matt-black paint. The instrument can-
not measure through transparent surfaces such as glass. In-
stead it measures the surface temperature of the glass.
Many organic materials and surfaces have an emission factor
of approx. 0.95. A table showing the emission factors of
various materials can be found in chapter 15.
The infrared thermometers have a function (see chapters
10 - 11) which enables adjustment of the emission factor
within a range from 0.10 to 1.00 µm so that exact measure-
ments can be obtained for various materials.
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