Teledyne 402REU - Hydrocarbon analyzer User Manual

Page 22

Teledyne Analytical Instruments

3-4

Chapter 3

Model 402

R-EU

module. Gas connections to the instrument are made at the

" or

stainless steel tube fittings provided on the rear panel. Note that the Purge
and Sensor Vent fittings are

" while all other gas connections are

Before tubing is connected to the system, it must be decontaminated

to rid it of hydrocarbon deposits. Using a small torch, heat each length of
tubing, while passing nitrogen through it, until it glows red. Begin at the
nitrogen source end and proceed down the length of the tube, “chasing” the
red glow (and hydrocarbon deposits) down to the open end of the tube. Cap
tubing while not in use with suitable non-contaminating caps.

All sample, calibration, and supporting gas lines which deliver into

the analyzer must be decontaminated before connection; vent lines do not.

When connecting the various gas lines to the system, be absolutely

certain that no “dead ends” are left; that is, no unused branch lines should
be left capped off, where pockets might form of material that is not repre-
sentative of the current contents of the line, or which might keep contami-
nants from being purged out of the system.

3.2.1

Supporting Gases

Normally, four supporting gases of different composition (see Chapter 4:

Equipment) will be required to operate the analyzer. The recommended
composition of these gases is specified in the Application Data section of
the Appendix. The gases should be supplied from cylinders that are
equipped with the type of regulator specified in the aforementioned sec-
tions.

CAUTION: Under no circumstances should you employ a regulator that is

not equipped with a metallic diaphragm anywhere in the system.
The regulators should be inspected prior to installation to be
sure that they are oil-free. Failure to comply with these direc-
tives will result in a constant drift in analyzer output, as organic
compounds will outgas into the plumbing system at a rate that
is related to the ambient temperature. Use 316 stainless steel,
dual-stage regulators only in fuel, sample, and blanket air lines;
shutoff valves should be used downstream from each regulator.

Place the supply cylinders as close to the analyzer as possible, and

interconnect them to the analyzer with new tubing. Be sure that all plumb-
ing connections are free of leaks.

NOTE: Use only stainless steel tubing within the analyzer and throughout

the system. Consult the assembly, piping, outline drawings, and
any Addenda included with this manual to determine if special
conditions apply.