Vaisala HMP260 - Manual (Page 57)

HMP260 SERIES
HMP260-U017en-1.5 Operating Manual
1997-11-25 51
When errors have occurred, the transmitter outputs the error code (see Appen-
dix 3 for all error messages):
>ERRS
E40 f ( all ) out of range
>
7.3 Changing the HUMICAP ® sensor and the filter
Remove the damaged sensor and insert a new one. Handle the sensor by the
plastic socket. DO NOT TOUCH THE SENSOR PLATE. 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 Measurement of output currents using test points
If a current output has been connected e.g. to a process computer, the output
current cannot be measured at the output connector X2 without disconnecting
the external load. The output current can, however, be measured at test points
CH1+/CH1- and CH2+/CH2- without disconnecting the output wires. These
test points can therefore be used in one point offset correction against an accu-
rate reference or in checking the current output without disconnecting the
analogue output from the process.
X2
OPENED COVER OF THE HMP260
X15
CH2
CH1 +
+
CH
1
+
CH
1
-
CH
2
+
CH
2
-
Fig. 7.3 Location of the CH1 and CH2 test points