23 - EN
4.8 Oxygen Sensor Calibrationn
The O
2
sensor(s) should be checked every 3 months and calibrated, if
required, using a calibrated gas supply.
Note.
The purity of the calibration gas should be as close to the production gas
purity as possible (minimum of 50ppm).
Do not exceed 7bar g (101.5psi g)
pressure
.
If the generator is fitted with a second O
2
sensor for EST (as illustrated)
both sensors must be calibrated at the same time.
For low purity applications the calibration may be performed using compressed
air. This method is not recommended when the purity of the gas is critical.
1
Navigate to menu 3.2 and enable the Oxygen Alarm Over-ride.
2
If using a calibrated gas supply - connect the gas to the Calibration Port
on the side of the generator.
3
Locate the calibration ball valve and rotate the handle clockwise so that it
is pointing towards
Calibration from Calibrated Gas position
.
Note. The calibration ball valve should be left in its original position if
using compressed air.
4
Rotate the handles of the Outlet Gas O2 Sensor ball valve and the CMS
Gas O2 Sensor ball valve (if fitted) 180
o
so that they are pointing towards
the
Calibration
(as indicated on the calibration label).
5
Wait approximately fifteen minutes for the O2 reading to stabilise.
6
Navigate to menu 3.3 and press
.
Using the
and
keys enter the purity of the calibration gas.
Press
to send the calibration level to the O2 Analyser.
On successful completion of the calibration the new O
2
reading will be
shown on the bottom line of the display.
If the calibration is not successful the original reading from the analyser
will be loaded. Should this occur repeat the above steps.
7
Repeat step 6 for the EST sensor (if fitted) in menu 3.4.
8
On completion of the calibration, return the ball valves back to their
original position and remove the regulated calibration gas supply as
applicable.
9
Navigate to menu 3.2 and disable the O2 Alarm Over-ride.
When returning to the main operating menu, “CAL” will be shown on the
top line of the display. This will remain for a period of twenty minutes after
the calibration. Throughout this time period the O2 alarm is overridden, to
allow the sensor(s) to return to the required level.
The following procedure must be carried only be performed by a Responsible Body or Service Personnel only.
Operators should not perform this operation.
Hot surfaces and hazardous live voltages. Take care when performing the following calibration procedure as there are hazardous live
voltages and potentially hot surfaces within the enclosure.
Note.
The ball valves are shown in the normal operation position and should be
returned to this position on completion of the calibration.
1
Calibration Port
2
Calibration ball valve
3
Outlet Gas O2 Sensor
4
Outlet Gas O2 Sensor ball valve
5
CMS Gas O2 Sensor (EST)
6
CMS Gas O2 Sensor (EST) ball valve
