Teledyne LGA-3500 - Laser Gas Analysis system - Manual (Page 83)

Laser Gas Analyzer Maintenance and Calibration
Teledyne Analytical Instruments 69
or adjustments to the optical transmission alignment are needed (see
section 6.1.3). If there is no significant decline in transmittance, you can
prolong the maintenance interval. When the transmittance does drop,
shorten the maintenance interval.
In addition, the warning alarm relay triggers when the transmittance
is lower than 30%. The corresponding alarm message appears on the
LCD front panel (please refer to Table 5.2 for detailed alarm
information) to remind the user to maintain the system.
Use the following procedure to clean the optical parts:
CAUTION: LASER RADIATION CAN CAUSE DAMAGE TO THE
EYES. POWER MUST BE DISCONNECTED DURING
SYSTEM MAINTENANCE.
CAUTION: DO NOT REMOVE THE TRANSMITTER OR
RECEIVER UNITS WHEN THERE IS GAS FLOW IN
THE ENVIRONMENT UNDER TEST WITHOUT FIRST
CLOSING THE VALVE BETWEEN THE UNITS AND
THE PROCESS FLOW.
1. Turn off the power supply to make sure that the transmitter unit
does not emit during the maintenance process.
2. Loosen the mounting nut and remove both the transmitter unit
and the receiver unit from the instrument flanges. Make sure the
cable connection between the transmitter unit, the receiver unit
and the central processing unit are not affected.
3. Check the contamination of the optical parts and look for
possible damage (such as cracks). If there is any damage to the
optical part, they must be replaced (Please contact TAI technical
support center).
4. Clean the optical parts with a mixture of alcohol and ether, then
dry with clean compressed air.
5. If the optical parts cannot be cleaned completely, they should be
replaced . (Please contact TAI technical support center).
6. Reinstall the transmitter and receiver units, and turn on the
power supply.