Teledyne LGA-3500 - Laser Gas Analysis system - Manual (Page 33)

Laser Gas Analyzer Installation
Teledyne Analytical Instruments 19
Open the gas supply and set the regulator to the proper pressure.
Turn the needle valve on the flow meter to the maximum, and then
adjust the needle valve adjacent to the flow meter to get the required
flow rate.
CAUTION: THE PURGE FLOW SHOULD REMAIN ON AFTER
THE POWER TO THE UNIT HAS BEEN TURNED OFF.
THIS PREVENTS DUST AND OTHER POLLUTANTS
IN THE ENVIRONMENT UNDER TEST FROM
CONTAMINATING THE OPTICAL DEVICES IN THE
TRANSMITTER AND RECEIVER UNITS.
Figure 3.6 Typical Purging System for the Model 3500
3.6 Electric Wiring and Connection
Depending on the instrument configuration, the Model 3500 Laser
Gas Analysis System can be categorized as Non-fiber optic and Fiber
optic. Non-fiber optic models (C option) use diode lasers without a fiber
pigtail. In these models, the laser diode is located in the transmitter unit.
The fiber optic models (F option) use a fiber pigtail to transmit the laser