Teledyne 3110 – Portable Trace/Percent Oxygen Analyzer, unapproved version - Manual (Page 22)

Installation Model 3110
22 Teledyne Analytical Instruments
2.4.2 Bleeding the Regulator and Purging the Gas Line
When using bottled gas (gas cylinder) as a calibration gas for trace
analysis applications, the regulator and sample lines must be bled to
remove traces of trapped air. Otherwise air that is trapped in the lines
especially between the regulator and cylinder will result in a lengthening
of the calibration time.
To bleed the regulator and sample line:
1. Attach the regulator to the gas cylinder. Then attach a sample
line with a flow control/shut off valve preferably at the far
end of the sample line.
2. Open the shut off valve slightly, and then open the valve on
the gas cylinder.
3. Adjust the regulator to the desired pressure (usually 5 psi)
then close the cylinder valve.
4. Open the cylinder valve to pressurize the regulator fully then
close the cylinder valve again.
5. Open the sample flow control valve and allow the gas to
bleed down and vent to a safe area. Observe the secondary
gauge (low pressure side) on the regulator. As the low
pressure gauge starts to fall, close the sample flow control
valve.
6. Repeat steps 4 and 5 seven (7) times.
The sample delivery system is now purged and ready for calibration
or analysis. Keep the cylinder valve open to maintain system
pressurization.
Note: Make sure there are no leaks in the sample line and
regulator connections. Check also the cylinder connection
for leaks.
2.5 Set the Sample Flow rate
Once the system has been calibrated, the instrument can be brought
to the analysis site and the sample gas line can be connected to the unit.
Using the quick disconnect fittings supplied; connect the vent line
followed by the sample line to the rear panel. See Figure 2-1.
Once the sample gas is flowing, set the flow rate to 0.2-2.5 SCFH.