Calibration – Vaisala HM40 User Manual
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Calibration
The humidity measurement accuracy of the HMP113 probe
should be checked once a year. You can do this yourself
using a humidity reference (for example, the Vaisala
Humidity Calibrator HMK15), or send the probe to a Vaisala
Service Center for calibration. See the back cover of this
manual for contact information.
If the calibration shows that the measurement accuracy is no
longer within specification, the probe must be adjusted. If
accuracy cannot be restored with adjustment, the probe
must be replaced. All probes that are ordered from Vaisala
are delivered calibrated. See section Accessories and Parts
on page 40.
If you think the meter is not measuring humidity or
temperature correctly, calibration and adjustment is
not the first thing to do. Try the following first:
- Make sure nothing is interfering with the
measurement: heat sources, temperature
differences, or condensation.
- Check that there is no moisture on the probe. If
the sensor has become wet, you must allow it
to dry before you can measure.
- Always wait for the measurement to stabilize.
For an introduction to calibration, order or
download the free calibration book from Vaisala at
the following address: