Dewpoint Temperature
The temperature to which the gas must be cooled in order that it should be
saturated with water vapour (i.e. 100% relave humidity). For praccal reasons it
is referred to dewpoint above 0 °C and frostpoint below 0 °C.
Parts Per Million by Volume
ppm(v) is the rao of the water vapour pressure to the total gas pressure.
Parts Per Million by Weight
ppm(w) is the rao of the molecular weight of water vapour to the molecular
weight of the carrier gas mixture.
11.6 Problem Guide
33
Fault Explanaon Required Acon Notes
Unit does not turn on.
Screen remains blank
and back light o.
Baery low level. Connect a baery
charger unit for
a minimum of 12
hours charging.
AutoCal failure. Sensor sensivity
too low.
Repeat AutoCal. If AutoCal fails,
contact supplier
to replace sensor.
Unit always reads
lower limit.
Sensor cable
broken.
Repair cable.
Unit will not dry down
to lower limit.
Sieve wet. Perform service on
unit using Service
Kit.
Service Kit
available from
supplier.
‘O’ ring failure. Perform service on
unit using Service
Kit.
Service Kit
available from
supplier.
Baery has short life
between charges.
Baery reaching
end of life.
Return to supplier/
authorised
distributor
for baery
replacement/
exchange.
Order from
supplier.
Keypad damaged. Check funcon
of keypad
electrically.
Contact supplier.