User's Manual

Routine Maintenance & Cleaning
76
4. Disconnect the cable from the red oxygen cell. It may be advantageous to gently
prize the locking tab of the connector away from the mating half, to facilitate
disconnection.
5. Unscrew the cell by hand (unscrew counter-clockwise). If discarding the cell,
place to one side for later safe disposal.
6. With the new cell, ensure the “O” ring is properly seated against the thread
abutment. Screw in the cell (clockwise) to hand-tightness but do not over-tighten.
Ensure a gas tight seal. Refit the connector and screw the ground lead to the
centre post, making sure the NOx cell ground lead is also secured.
7. Ensure the Oxygen Cell is properly seated in the housing and provides a gas tight
seal.
8. Refit the cover, make sure the gas tubing is not crushed or trapped and secure
cover to the back of the unit.
9. Turn on the power to the unit and allow it to warm up. Ensure that the analyzer
is fully warmed up (i.e. that it has had at least 5 minutes since power on).
10. Use handset to configure the OmiScan Gas with the new O
2
cell:
• Select ‘Renew O
2
Cell’.
• This will reset the error code and recalibrate the Analyzer with the new cell.
11. If the unit still fails, contact your service engineer.
The O
2
cell can be monitored to see if it is approaching the end of its life. This can be
done by checking its cell voltage. This should be done with the probe in clean air and
accessing the following menu on the handset:
• Select ‘Gas Analyzer’ – ‘System Checks’ – ‘O
2
Cell functions’ – ‘Oxygen Cell
Value’
A good cell should read between 9mV and 11mV. The Analyzer will automatically flag
up an error if the cell voltage falls below 7mV. It is recommended that the cell is
changed if voltage is nearing the 7mV threshold.
NOx Cell Replacement
In theory the NOx cell should have a life expectancy of 2 years. Unlike the O
2
cell, the
OmiScan Gas will not flag an error in the NOx cell.
It is recommended, therefore, that the NOx channel, like the rest of the OmiScan Gas,
is regularly tested with calibration gases of known concentration. This can be carried
out by an Omitec authorized Service agent.
NOTE: Due to the operating characteristics of the NOX sensor, any necessary
replacement will need to be calibrated by an authorized Omitec authorized Service
agent using a NOx calibration gas.