RKI Instruments 35-3000RK-LEL - Manual (Page 18)

18 • 35-3000RK-LEL Combustible Gas Sample-Draw Detector
Calibration
This section describes how to calibrate the combustible gas sample-draw detector. It
includes procedures to assemble the calibration kit, set the zero reading, set the response
reading, and return to normal operation.
The standard calibration gas for the sample-draw detector is methane. The sample-draw
detector may be calibrated to other combustible gases such as hexane or hydrogen. Use
the correct calibration gas for your installation.
NOTE: Calibrating the sample-draw detector may cause alarms. Be sure to put the
controller into its calibration program or disable external alarms before
continuing.
NOTE: This procedure describes calibration using a dispensing valve and a gas
collection bag. A demand-flow regulator calibration kit is also available for
calibrating the sample-draw detector without using a sample bag.
Preparing for Calibration
1. Follow the instructions in the controller’s operator’s manual for entering calibration
mode.
2. Connect the calibration kit sample tubing to the fitting on the gas collection bag and
run the tubing through the tubing clamp provided with the calibration kit.
3. Disconnect the incoming sample line from the sample-draw detector’s inlet fitting,
then connect the sample tubing from the gas collection bag to the inlet fitting.
Allow the sample-draw pump to draw out any residual gas in the gas collection bag.
4. Close the tubing clamp.
NOTE: This step will cause a low flow alarm.
5. Disconnect the calibration kit sample tubing from the inlet fitting.
NOTE: If you can verify a fresh air environment, it is not necessary to use a zero air
calibrating sample to set the zero reading at the controller. If you can verify a
fresh air environment, go to the next section, Setting the Zero Reading.
6. Screw the dispensing valve onto the zero air calibration cylinder.
7. Connect the tubing from the gas collection bag to the dispensing valve, then open the
clamp.
8. Open the dispensing valve. The gas collection bag begins to fill.
9. Close the dispensing valve when the gas collection bag appears full.
10. Close the tubing clamp, then disconnect the sample tubing from the dispensing valve.
11. Remove the dispensing valve from the zero air calibration cylinder.