RKI Instruments 35-3000RKA-10 - Manual (Page 20)

20 • 35-3000RK-10 PPM Hexane Sample Draw Detector
10. Place the controller and sample draw detector into operation
11. Verify that the flow rate is approximately 1.5 SCFH. If necessary, adjust the flow rate
with the bypass valve and/or the flow adjust pot.
12. Close the sample draw detector’s housing door.
Replacing the Ferrules
The inlet and exhaust fittings each includes two ferrules that seal the incoming or exhaust
tubing to the fitting. Replace the ferrules if the seal is bad or if you replace the sample
tubing. Always replace the ferrules as a set.
1. Unscrew the nut that holds the tubing to the fitting from the fitting.
2. Slide the nut away from the end of the tubing.
3. Cut off the end of the sample tube with the old ferrules off about one inch from the
end
4. Slide the nut off the sample tubing.
5. Position the nut so the threaded end is facing you, then insert the bottom (smaller)
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.
6. 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.
7. Screw the nut onto the fitting by hand just until it stops turning.
8. Insert the sample tubing into the fitting until it bottoms out.
9. Firmly tighten the nut so the ferrules crimp onto the sample tubing and make a seal.
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 making this adjustment
The factory-set low flow setting is 0.6 SCFH (±0.2 SCFH). To adjust the low flow setting:
1. Use the flow adjust pot (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 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.
The low flow adjustment screw is accessible through a circular cutout in the main
circuit board. See “Component Location” on page 5.
2. Slowly turn the low flow adjustment screw in very small increments counterclockwise
just until the sample draw detector goes into low flow alarm.
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 adjustment screw slightly
clockwise. Repeat Step 3 and Step 4 if necessary.