Vaisala HMP240 - Manual (Page 59)

HMP240 series
M210300en User's Guide
57
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When errors have occurred, the transmitter outputs an error code (see Appen-
dix 4 for all error messages):
>ERRS <cr>
E40 f ( all ) out of range
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7.3 Replacing the composite sensor
The humidity and temperature sensors (HUMICAP

H-sensor and Pt100)
have been glued together. If one or both sensors are damaged, the whole
composite sensor must be changed.
•
Cut the pins of the Pt100 sensor at the top.
•
Lift the humidity sensor gently.
•
Loosen the pins of the Pt100 sensor by soldering.
•
Remove the old tin from the connectors.
•
Put a new humidity sensor in place.
•
Bend the pins of the Pt100 sensor carefully into the connectors.
•
Fasten the pins by soldering them with Multicore 96S-Flux 381.
•
Make sure the solder joints are good and check that the pins are not
short-circuited.
•
Remove possible splashes from the solder joint with distilled water,
but take care not to damage the humidity sensor.
After sensor change the humidity calibration must be done according to the
instructions in Chapter 6.1.3.
Replace a dirty membrane or sintered filter to ensure a maximum lifetime for
the sensor. Do not try to clean the filter. The sensor can be cleaned with dis-
tilled water; if this does not work, replace the sensor.
7.4 Temperature channel (additional) adjustment with Pt 100 simulators
Switch the power off and disconnect the wires to the Pt 100 sensor from solder
lugs TP1, TP2 and TP3.