18 • 35-3010A-13 Sample-Draw Detector
Start Up
This section describes procedures to start up the sample-draw detector and place the sample-draw
detector into normal operation.
Introducing Incoming Power
1. Complete the installation procedures described earlier in this manual.
2. Verify that the power wiring to the controller is correct and secure. See the controller operator’s
manual.
3. Turn on or plug in the incoming power at the controller, then turn on the controller.
4. Verify that the Pilot light is on at the sample draw detector.
5. Verify that the controller is on and operating properly.
6. Verify that the flowmeter indicates a flow rate of approximately 1.2 SCFH. If necessary, use the
bypass valve or flow adjust potentiometer to adjust the flow rate.
NOTE:
The following step tests for leaks in the sample line. This test may cause a low flow condition
at the sample-draw detector.
7. Verify that the incoming sample line is not leaking. To test the sample line, plug the open end of
the sample line with your thumb. If the flowmeter ball drops to the bottom of the flowmeter, the
incoming sample line is not leaking.
8. Remove your thumb from the sample line, press the pump reset switch, and verify the flowmeter
returns to a normal flow rate.
Setting the Zero Reading
CAUTION:
If you suspect the presence of combustible gas or an abnormal oxygen condition (not
20.9%) in the monitoring environment, use the calibration kit and the zero air calibration
cylinder to introduce “fresh air” to the sample draw adapter and verify an accurate zero
setting.
As shipped from the factory, the H
2
sensor is zeroed with N
2
and calibrated with H
2
in N
2
. If the
sample area has a background that is not N
2
(such as fresh air or helium), you must rezero the H
2
sensor while applying that background gas. This means you may need to zero the H
2
and O
2
sensors
separately.
1. For H
2
: Screw the regulator into a calibration cylinder containing the background gas (such as zero
air or helium). Connect the sample tubing from the regulator to the inlet line at or near the sample-
draw detector’s INLET fitting. Allow the calibration gas to flow for one minute.
For O
2
: Verify that the sample-draw detector is sampling a fresh air environment (environment
known to be free of combustible gas and of normal oxygen content, 20.9%).
2. Open the housing door.
3. Set a voltmeter to measure in the millivolt (mV) range.