Jeulin 545 017 Mode D'emploi page 12

Geology
Radiation meter
Ref :
545 017
3.2
Remove the white sheet and read the reflectance value on the screen.
This value as a percentage is the reflectance of the substance studied in the spectral band
corresponding to the filter used.
Repeat these operations with the other available filters to obtain 4 points on the reflectance
curve of the substance. An example is given below.
3.3
The analogue output signal is 0-1 V for a connection to a CAT console or to a multimeter.
To obtain the reflectance, record the voltage in Volts and convert it to %.
For example, if the voltage is 0.2 V, the reflectance is 20%.
It is essential to calibrate the instrument for
each wavelength.
The wavelengths for each filter are given at
the end of these instructions.
Example acquisition of the reflectance of earth
placed in a Petri dish as a function of the
wavelength.
4. Precautions for use
Radiation meter measurements require very strict working conditions:
ENGLISH
- Case No.3:
Hi
The display shows
diaphragm has to be changed. In this case, the zero setting must be made again and
then the maximum setting must be made again.
Measurement
External analogue outputs

The target aimed at must be on the optical axis of the radiation meter and within the
observation field.

Avoid shadows created on the target by the radiation meter, the operator, spectators
or surrounding objects.
Changes in the position of the experimenter, his hands or spectators can change
illumination conditions.

Measurements are usually made in varying width spectral bands, rather than in
monochromatic light.
distribution of the light source and is slightly different depending on whether the
measurement is made in daylight (different at midday and at sunset) or under an
incandescent lamp or a fluorescent lamp or even in the light of a room with coloured
curtains.

Since the brightness of the target can vary, specular reflection (as from a mirror) can
mask diffuse reflection or transmission if the angle of inclination relative to the light is
badly chosen.

Put matt black Canson paper behind the targets to prevent hindering reflections.
which means that the light power is badly adapted. The
The measurement result then depends on the spectral
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