Teledyne LGA-3500 - Laser Gas Analysis system - Manual (Page 27)

Laser Gas Analyzer Installation
Teledyne Analytical Instruments 13
3.2.2 Choosing Installation Spot
It is strongly recommended to install the system probes on a
straight section of the gas flow pipeline to ensure uniformity of the gas
flow. The length of straight pipe before the installation spot should be at
least twice (5 times, recommended) as much as the diameter of the pipe,
and half (twice, recommended) after the installation spot.
Note: The laser gas analysis system measures the average
concentration along the laser beam path (see Figure 1.2).
If there is no straight pipe section for mounting the flanges,
it may still be possible to get accurate measurements.
(Please contact our technical support center).
In addition, the installation spot should be chosen carefully
considering both safety and ergonomic factors. A platform should be
constructed when the chosen spot is not fully accommodating.
3.3 Analysis Section Installation
Installation of the analysis section involves:
• Welding flanges onto the process pipe
• Installing instrument flanges
• Checking the offset angle using the laser pen
• Adjusting the coaxial angle of the two instrument flanges,
• Installing the transmitter unit and the receiver unit.
3.3.1 Welding Flanges
The transmitter and receiver units of the analysis section are
mounted on DN50 flanges and mate to corresponding flanges which
must be welded onto the process pipe.
Note: The customer is responsible for correct welding of the
flanges onto the process pipe. The use of a competent
professional welder is required to ensure proper placement
of the flanges and provide a leak-free weldment.
The precision adjustment between the welding flange and the
instrument flange with the supplied O-ring can fine tune the optical
transmission to a limited extent. This allows for the two welding flanges