14
9.0 Maintenance
9.1 Humidity calibration and adjustment
Depending on the application and the requirements of certain industries, there might arise the
need for periodical humidity calibration (comparison with a reference) or adjustment (brining
the device in line with a reference).
Calibration and adjustment at Setra
Calibration and/or adjustment can be performed by the Setra calibration laboratory. For
information on the Setra capabilities in ISO or accredited calibration visit www.setra.com.
Calibration and adjustment by the user
Depending on the level on accuracy required, the humidity reference can be:
• Humidity calibrator - Purchased separately (not currently sold by Setra)
• Hand held device - Purchased separately (not currently sold by Setra)
• Calibrated salt solutions - most economical
9.2 Temperature calibration and adjustment
Due to the outstanding protection of the temperature sensing element integrated in the Setra
sensor, a drift of the T measurement is rather unlikely. If adjustment seems necessary, the
user can perform a one or two point T adjustment with PCA and PCS against a reference
of choice, it is highly recommended to return the device to the manufacturer for this. The
reasons rest on the difficulty of an accurate T calibration in the air. Out calibration shall take
into account the self-heating of 8RH200 with closed enclosure, in its real mounting position
and in continuous operation. The impact of the output current and of the probe orientation to
the self-heating, as well as the cooling effect of the air circulation in the climate chamber used
for calibration.
9.3 When employed in dusty, polluted environment
The filter cap shall be replaced once in a while with a Setra original. A polluted filter cap causes
longer response time of the device.
If needed, the sensing head can be cleaned. For cleaning instructions please see
www.setra.com.
