RKI Instruments 35-3001A-11 - Manual (Page 21)

35-3001A-11 Hydrogen Sample-Draw Detector • 17
NOTE: When the sample-draw detector is first powered up with a new amplifier, the initial
output may be either high or below zero depending on the setting of the zero pot. Be sure
to make arrangements so that this does not cause unwanted alarms.
10. Turn on power to the controller.
11. Turn on the controller and place it into normal operation.
12. Allow the sample-draw detector to warmup for 5 minutes.
13. Calibrate the sample-draw detector as described in “Calibration” on page 18 of this manual.
Replacing the Hydrophobic Filter
1. Open the housing door of the sample-draw detector.
2. Disconnect the filter from the rubber elbows on each end of the filter, then remove the filter
from the sample-draw detector.
3. Install the new filter. Be sure the side of the filter marked “INLET” is connected to the elbow
that is connected to the inlet fitting.
4. Verify that the flow rate is approximately 1.0 SCFH, then close the housing door.
Replacing the Particle Filter
1. Disconnect the tubing routed to the sampling area, if installed, from the particle filter.
2. Disconnect the particle filter from the inlet fitting’s tubing stub.
3. Install the new particle filter onto the inlet fitting’s tubing stub. Be sure the arrow on the
particle filter is pointing toward the inlet fitting.
4. Reinstall the tubing routed to the sampling area.
Adjusting the Low Flow Setting
NOTE: Adjusting the low flow setting will cause a low flow alarm at the sample-draw detector
and a fail alarm at the controller. Be sure to put the controller into its calibration program
or disable external alarms before performing this test.
The factory-set low flow setting is 0.6 SCFH (±0.1). To adjust the low flow setting:
1. Use the sensor flow control valve to set the flow to 0.6 SCFH. Turn the valve’s knob
counterclockwise to increase the flow and clockwise to decrease the flow.
If the sample-draw detector goes into low flow alarm before you can adjust the flow down to
0.6 SCFH, adjust the pressure switch adjustment screw 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.
NOTE: The pressure switch adjustment screw is accessible through a circular cutout in the
flowmeter circuit board.
2. Slowly turn the pressure switch adjustment screw counterclockwise just until the sample-draw
detector goes into low flow alarm.
3. Turn the sensor flow control valve’s knob counterclockwise to increase the flow until the unit
is out of low flow alarm.
4. Decrease the flow very slowly by turning the sensor flow control valve’s knob clockwise and
verify that the low flow alarm is 0.6 SCFH (±0.1).