Teledyne T200, Руководство по эксплуатации, Страница: 227 / 425

Teledyne API
– T200 NO/NO
2
/NO
X
Analyzer Operation Manual Instrument Maintenance
225
11.3.12. CHECKING FOR PNEUMATIC LEAKS
C
AUTION
- T
ECHNICAL
I
NFORMATION
Do not exceed 15 psi when pressurizing the system during either Simple or
Detailed checks.
11.3.12.1. SIMPLE VACUUM LEAK AND PUMP CHECK
Leaks are the most common cause of analyzer malfunction. This section presents a
simple leak check, whereas the next section details a more thorough procedure. The
method described here is easy, fast and detects, but does not locate, most leaks. It also
verifies the sample pump condition.
1. Turn the analyzer ON, and allow at least 30 minutes for flows to stabilize.
2. Cap the sample inlet port (cap must be wrench-tight).
3. After several minutes, when the pressures have stabilized, note the SAMP (sample
pressure) and the RCEL (vacuum pressure) readings.

If both readings are equal to within 10% and less than 10 in-Hg-A, the
instrument is free of large leaks.

It is still possible that the instrument has minor leaks.

If both readings are < 10 in-Hg-A, the pump is in good condition.

A new pump will create a pressure reading of about 4 in-Hg-A (at sea level).
11.3.12.2. DETAILED PRESSURE LEAK CHECK
If a leak cannot be located by the above procedure, obtain a leak checker that contains a
small pump, shut-off valve, and pressure gauge to create both over-pressure and
vacuum. Alternatively, a tank of pressurized gas, with the two-stage regulator adjusted
to ≤ 15 psi, a shutoff valve and a pressure gauge may be used.
ATTENTION
COULD DAMAGE INSTRUMENT AND VOID WARRANTY
Once tube fittings have been wetted with soap solution under a pressurized
system, do not apply or reapply vacuum as this will cause soap solution to be
sucked into the instrument, contaminating inside surfaces.
1. Turn OFF power to the instrument and remove the instrument cover.
2. Install a leak checker or a tank of gas (compressed, oil-free air or nitrogen) as
described above on the sample inlet at the rear panel.
3. Disconnect the pump tubing on the outside rear panel and cap the pump port.

If IZS or zero/span valves are installed, disconnect the tubing from the zero and
span gas ports and plug them (Figure 3-3).

Cap the DFU particle filter on the dryer.
4. Pressurize the instrument with the leak checker or tank gas, allowing enough time
to fully pressurize the instrument through the critical flow orifice.

Check each tube connection (fittings, hose clamps) with soap bubble solution,
looking for fine bubbles.
06858E DCN7057