Casella CEL Microdust Pro real time dust monitor - Manual (Page 48)

MicroDust Pro Aerosol Monitoring System
48 Casella CEL
8.3 Servicing hints
There are no user-serviceable parts inside the MicroDust Pro instrument or
sampling probe. DO NOT open these items. Repairs should be performed only
by authorised engineers.
IMPORTANT
If you suspect the instrument has an electrical fault, or if a fault persists after you
perform the servicing hint listed below, return the instrument to Casella CEL for repair..
Table 2. Servicing hints
Fault symptom Possible cause Service hint
The instrument does not
switch ON Battery is discharged or does
not charge (confirm whether
the charge indicator comes on
when you connect the charge) Recharge the batteries or fit
new batteries if necessary.
Use an external power supply.
The probe always reads zero A fault may exist on the infra-
red transmitter or receiver Check the probe connection.
There is a continuous ‘over
range’ indication Optical misalignment due to
mechanical shock
Excessive contamination Return the instrument to
Casella for optical alignment,
cleaning and re-calibration.
Zero is unstable or drifts when
the probe collar covers the
sampling chamber Sample chamber
contamination by dust or fibre Follow the technique in
section 8.1 “
Lens
contamination ” to clean the
sample chamber.
Follow the technique in “
Zero
adjustment ” on page 23.
A probe contamination
message is displayed Optical misalignment due to
mechanical shock
Excessive contamination Purge the probe with clean air
from the bellows pump.