Manual

Sample-Draw Hydrogen Sulfide Gas Detection • 13
ferrule into the nut. Insert the ferrule so the flat side is facing down.
NOTE: Make sure the bottom ferrule is laying flat in the nut.
4. Insert the cone-shaped front ferrule on top of the bottom ferrule. Insert the ferrule so
the smaller end of the cone is facing up.
5. Screw the nut onto the fitting, then connect the sample tubing to the fitting. Make sure
you firmly tighten the tubing to the fitting.
Adjusting the Low Flow Setting
The factory-set low flow setting is 0.6 SCFH (±0.2). To adjust the low flow setting:
1. Use the flow adjust potentiometer (VR1) to set the flow to 0.6 SCFH.
If the sample-draw detector goes into low flow alarm before you can adjust the flow
down to 0.6 SCFH, adjust the low flow potentiometer 1/4 turn clockwise, then
attempt to set the flow again. Repeat this step until you are able to adjust the flow to
0.6 SCFH.
2. Slowly turn the low flow potentiometer counterclockwise just until the sample-draw
detector goes into low flow alarm.
NOTE: The low flow potentiometer is accessible through a circular cutout in the main
circuit board. The cutout is labeled PS1.
3. Increase the flow using VR1 until the unit is out of low flow alarm.
4. Decrease the flow very slowly and verify that the low flow alarm is 0.6 SCFH (±0.2).
If the low flow alarm is set too low, turn the low flow potentiometer slightly
clockwise. Repeat steps 3 and 4 if necessary.
5. Use the flow adjust potentiometer (VR1) to set the flow to 1.5 SCFH.
6. Make sure the sample draw detector’s Fail light is off.