Easidew Plus Portable Hygrometer User’s Manual
12
97478 Issue 1, October 2014
MAINTENANCE
5
MAINTENANCE
Routine maintenance of the Easidew Plus Portable Hygrometer is confined to regular
re-calibration of the internal, removable polymer capacitive sensor and replacement of
the filter cartridge.
5.1
Calibration
The calibration of the internal sensor is traceable to national standards. For this reason
it should only be calibrated in an accredited, US
National Institute of Standards and
Technology (NIST) standards laboratory. If these facilities do not exist it is recommended
that the sensor returned to Kahn Instruments. A calibration certificate bearing a seven-
point calibration is issued with each sensor.
In most applications, annual re-calibration insures that the stated accuracy of the
Easidew sensor is maintained.
5.2
Sensor / Battery Replacement
To remove the sensor, or battery pack:
1.
Insure that the instrument is switched off and that the battery charger,
current output and any sampling components are also disconnected.
2.
Remove and retain the 10 Phillips-head screws from the top plate.
3.
Lift the small battery pack cover in the top right corner of the instrument.
A small flat bladed screwdriver may be required to gently pry the edges
of the cover if it has become stuck to the waterproof seal underneath.
Removing this cover first will make it easier to lift the entire top panel out
of the instrument.
4.
Lift the top plate of the instrument out of the case. Disconnect the battery
pack before removing the top plate completely to prevent it from straining
on the attached cable. If only replacing the battery pack, do not follow
the next two steps.
5.
Undo the screw from the center of the sensor connecting plug and pull
off the connector.
6.
Unscrew the sensor from the block.
Installing the replacement is simply a reversal of the above procedure. When installing
a new sensor it may be necessary to change the alignment of the GDSN connector (see
next page).
