Operation
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3-3
Analyzing a Gas Sample
Hydrogen gas is flammable, and in a mixture with air concentrations
above 4% - 5%, it is explosive. Vent the gas from the outlet to a safe
area - outdoors, if possible. Always make sure the workplace is well-
ventilated.
Taking a reading
1. Make sure that you have performed the
Current Adjustment
and
Electrical Zero Adjustment
if necessary.
2. Connect the inlet gas Swagelok tube fitting to the source gas to be
tested.
3. Turn Knob 1 to either
TEST
position (non-backlit/backlit).
4. Set the flow through the analyzer at a rate of about 50 ml/min. A
continuous, steady, flow rate of gas through the analyzer is preferred
since it will not affect the reading.
The rate of gas flow is not critical. However, do not take a digital read-
ing while hand pumping the gas sample. The pulsing could create a
flow effect that might alter the reading.
5. The reading is stable when the digital readout does not increase for 30
to 60 seconds.
A decrease in the reading may indicate that there is a leak in the sys-
tem and should be invesitgated. Follow the procedure “Checking for
Leaks” in Chapter 1.
If the sample gas is forced through the analyzer by pressure at the source
(rather than hand pumping), and then vented to atmosphere, connect a
short piece of rubber tubing (12” x 18” long) to the outlet gas Swagelok tube
fitting as a precaution against ambient air diffusing back into the analyzer.
6. Provide a low pressure (<5 PSIG), low flow rate source of air/nitrogen to
purge the gas passages in the analyzer of any residual gases.
When the analyzer is not in use, be sure to turn Knob 1 to the
OFF
position, otherwise the battery life will be decreased.
NOTE
NOTE
NOTE
