Problem: H
2
O
2
or humidity reading does not change during regular use for less than 5 minutes.
Possible Cause:
Solution:
Purge is being performed
(duration of the purge is 4
minutes).
No actions required.
Problem: H
2
O
2
or humidity reading does not change during regular use for more than 5 minutes.
Possible Cause:
Solution:
In analog mode: The scaling of
the output is unsuitable,
preventing the change from
showing.
Check and change the analog output scaling with Insight
software (see
Vaisala Insight Software (page 28)
In analog mode: The error level
is configured within the
measurement output level, and
the probe is in error state.
Check the probe diagnostics with the Insight software (see
Vaisala Insight Software (page 28)
Consider changing the analog output error level to be outside the
measurement scale.
Problem: Measurement reading appears incorrect.
Possible Cause:
Solution:
The temperature probe is
installed near a heat source or
too close to the H
2
O
2
and
humidity probe.
Change the location of temperature probe. See
for recommended installation locations.
The filter is wet.
Remove the filter, pour out any water, and let the filter dry.
Depending on air humidity and temperature, drying the filter in
ambient air can take from a few hours to a day. Alternatively, you
can dry the removed filter with nitrogen gas or dry pressurized
air. When the filter is dry, reinstall the filter.
Be careful not to touch the sensors when the filter is off the
probe.
Perform a chemical purge.
The filter is blocked or dirty.
Change the filter.
Be careful not to touch the sensors when the filter is off the
probe.
Condensation has formed on
the sensor when the probe was
powered off.
When the probe is powered off, exposure to H
2
O
2
condensation
can break the PEROXCAP sensor within a day, and the sensor will
not recover. When the probe is powered on, the heated sensor
withstands condensing H
2
O
2
conditions.
A sensor damaged with H
2
O
2
condensation during power-off
time cannot be repaired.
Chapter 9 – Troubleshooting
37