Maintenance
EGM-4 Operator's Manual – Version 4.19
- 44 -
Maintenance
The EGM-4 is virtually maintenance free. However, there are a few items that should be
watched and cared for periodically.
Soda Lime Absorber Column
The soda lime absorber column is built into the EGM-4 and safely protected within the
enclosure. It should not require any maintenance with the exception of the soda lime
desiccant which will require replacement from time to time (See
on page 44). The
black aluminium cap, located on the back of the instrument, is fitted with an “O” ring with a
grey foam filter between it and the desiccant. The “O” ring should be kept fresh by applying a
slight smear of silicone grease from time to time. If this “O” ring gets to dry, it could crack or
even break which will lead to a leak in the system and errors in Analyzer ZERO. The black
aluminium cap can then be removed and the contents emptied when required. When
replacing the soda lime, the column should be tapped to ensure tight packing and the cap
replaced as found. Over time, the grey foam filter may require replacement. If so, contact PP
Systems (
PP Systems’ Contact Information
on page 7).
It is sensible to examine the absorber column each time the contents are replaced as any
leakage of ambient air into the gas circuit generally causes error messages during “Autozero”
operation or fluctuating CO
2
concentration during measurement.
Soda Lime
Soda Lime is supplied as self-indicating granules (1-2.5mm) which turn from green to brown
as it becomes exhausted. This desiccant should be replaced when it is two-thirds exhausted
(brown). Soda Lime cannot be regenerated and should be discarded when exhausted.
Frequent replacement should not be required under normal circumstances. The amount of
change is highly dependent on the “Auto-Zero” frequency. Under normal operating
conditions, this desiccant is changed approximately 1 time per month. See
on
page 44.
For accurate measurements and calibration, it is absolutely critical that the EGM-4 absorber
column is not exhausted. If the soda lime is becoming exhausted, it will cause the ZERO to
be performed on non-ZERO air causing an error in the calibration.
! CAUTION !
WASH YOUR HANDS AFTER HANDLING SODA LIME
