LumaSense Technologies IGA 740-LO User Manual
Page 22
18
7.2
Adjusting the Parameters
7.2.1 Emissivity
The emissivity is the relationship between infrared energy radiated from an object and
the radiation energy of a perfect emitter (black emitter) at the same temperature and
the same spectral range.
The emissivity is material-dependent and of a considerable size in order to be able to
determine the temperature of an object accurately without contact. The emissivity of the
object being measured must therefore be known and be adjusted at the pyrometer.
Adjust the emissivity suitable for the measurement in accordance with the procedural
steps on page 18. The adjusted emission value is indicated in the main menu.
Typical emissivities for various materials are available on our homepage at
under practical knowledge or in relevant literature.
emissivity less than 1.0. This difference can be stepless adjusted between 0.1 and 1.0
with the potentiometer at the back of the instrument.
1.
First measure the real temperature of measuring object with a contact ther
mometer e.g. thermocouple or resistance probes. The “black” temperature
(spectral temperature) measured with a pyrometer adjusted to emissivity =
1.0 usually gives a measuring value differing to real temperature because of
the real emissivity of <1.0. The value given by the instrument usually will be less
than the real temperature. The emission ratio of most materials depends on
temperature as well as wave length being measured.
2.
You can get a correlation of the temperature scales, if you adjust the pyrometer
at the exact temperature with the help of the potentiometer of emissivity.
After adjusting the emissivity factor through a correlation measurement
you can now measure temperatures for the calibrated temperature range
at an accuracy mentioned in the technical data.
IMPORTANT
Please pay attention if you take over table values of emissivity to give
the value of emissivity factor at a certain wave length. Adjusting
emissivity following table values is not as exactly as adjusting following
a comparing measurement.
Changing emissivity:
With the help of a suitable screw driver and without any violence you can adjust
emissivity at the rear side of the pyrometer stepless between 0.1 and 1.