E C O P H Y S I C S Installation
CLD 780 TR / July 2000 29
4.2.3 Installing the gas tubing between the CLD 780 TR and its
peripherals
(see Fig. 4.2).
1. Sample tubing [2] must be installed between the sample extraction
point and the analyzer sample inlet [1]. Tubing material should be
PTFE, PFA or other fluorinated plastic, or glass. Provision of a sample
gas filter is the responsibility of the operator.
2. Connect the dry air tubing [4] between the two silica gel drying car-
tridge [F] and the inlet marked “Dry Air PMT” [3] on the front panel.
3. Connect the oxygen tubing [6] between the silica gel drying cartridge
[F] and the inlet marked “O
2
Ozone Generator” on the front panel [5].
Note: Although the ozone generators may also be operated with a dry
air supply, they are designed for optimum operation with oxygen. Opera-
tion with an oxygen supply therefore gives the best analyzer performance
and is to be preferred.
How set up the O
2
supply correctly:
– Connect a precision two stage pressure regulator [18] to the oxygen
cylinder [17].
– Install a needle valve [19] downstream of the pressure regulator to al-
low precise regulation of the oxygen flow.
– About 30 % of the O
2
stream should be allowed to flow into the bleed
line from the T-connector [20]. The bleed line should vent to open air
and be at least 2 m long. A flow meter [21] on the bleed line ensures
that sufficient O
2
flows out to prevent atmospheric air back-flow into the
instrument and a silica gel cartridge [F] protects against the possible
ingress of atmospheric moisture. This arrangement insures that the
Attention: The following notes apply to the standard CLD 780 TR in-
strument. Before installing an analyzer fitted with options, please read
Appendix A4.
Important: Keep the sample tubing as short as possible! (See section.
7.1)
Important: Always stand the silica gel drying cartridges vertically up-
right, with the metal lid facing downwards.
!
WARNING
Pressurized gas!
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