Metrological laboratory
RELATIVE HUMIDITY MEASUREMENTS
Instruments to be calibrated by Sit Centre no.124:
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electrical hygrometers and thermohygrometers (*)
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thermohygrometers transmitters (*)
mechanical hygrographs and thermohygrographs (*)
electric psychrometers
(*) (measuring range from 10% RH to 92% RH at air temperature from 0°C to 60°C)saturated salt solutions
(measuring range from 10% RH to 90% RH at the air temperature of 23°C)Condensing mirror hygrometers
(measuring range from -20°C to 60°C)
The SIT certificate has to be requested at the time of placing the order, otherwise it's necessary to send the instrument back to the Centre for certification.
On request, and only if necessary details are available, the instrument setting can be carried out before certification; the relevant charge has to be previously stated.
At the time of placing the order it's necessary to specify the kind of Isotherm requested.
Minimum points, for the requested Isotherm, are those suggested by the Primary Institute.
Certification will be according to the available equipment.
All the instruments of other manufacturers sent for certification have to be provided with their instructions manual.
UNCERTAINTY WITH WHICH THE SIT CENTRE WAS APPROVED FOR RELATIVE HUMIDITY
| MAGNITUDE |
INSTRUMENTS TO BE CALIBRATED |
MEASURING RANGE |
UNCERTAINTY(*) |
| relative humidity |
Electric and mechanical hygrometers and thermohygrometers
Electric psychrometers |
from 10%RH to 92%RH (at air temperature from 0° to 60°C) from 10%RH to 92%RH (at air temperature from 0° to 60°C) |
from 0.5%RH. a 1.8%RH. from 0.5%RH. a 1.8%RH. |
| relative humidity | Saturated salt solutions |
from 10%RH to 90%RH (at air temperature from 20° to 25°C) |
1.4%RH |
| dew point | Condensing mirror hygrometers | from -20°C to 60°C | 0.16°C |
