Calibration methods
Air humidity measurement
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ETALONNAGE
ACCREDITATION
N°2.21
HYGROMETRIE |
Calibration in climatic chamber by comparison with a reference
hygrometer: the dew point temperature is measured with a reference hygrometer.
The temperature measurement is performed with a reference thermometer put near
the sensor to be calibrated. The reference relative humidity is calculated from
those two measurements.
Measurement of temperatures
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ETALONNAGE
ACCREDITATION
N°2.1116
TEMPERATURE |
Three methods are used according to the field of temperature:
- Between -30 and +160°C, the calibration is performed
in a climatic chamber by comparison with a 100-ohm platinum
resistance thermometer.
- Between -30 and +215°C, the calibration is performed
in an overflowing thermostatically controlled bath, by comparison with a 25 - ohm reference platinum resistance
thermometer. Depending on the temperature, the liquid used
is either alcohol, water or oil. The thermometer probe
must be at least 60 mm long for a diameter below or equal
to 6 mm,
150 mm long for a diameter over 6 mm.
- Between +200 and +1100°C, the calibration is performed
in a special furnace by comparison with a type S thermocouple.
The diameter of the thermocouple to be calibrated must be below 10 mm
and its length must be over 270 mm.
Measurement of air velocities
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ETALONNAGE
ACCREDITATION
N°2.58
ANEMOMETRIE |
The calibration of the anemometers is performed in a wind tunnel,
by direct comparison with a reference.The reference device used by the laboratory over
the whole velocity range is a laser-Doppler anemometer (L.D.A.)
Calibration conditions
The calibration conditions are the same that for the one-function instruments.
Please refer to the corresponding information.
Measurement of pressures
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ETALONNAGE
ACCREDITATION
N°2.160
PRESSION |
The calibration of manometers or pressure sensors is performed by direct comparison
with a reference. The generated pressure is measured in parallel on the reference
and on the pressure sensor to be calibrated.
Calibration conditions
The calibration conditions are the same that for the one-function
instruments. Please refer to the corresponding information.
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