35-3001-06H-DIL Hydrogen/Oxygen Sample-Draw Detector • 21
Calibration, Oxygen Sensor
This section describes how to calibrate the oxygen sensor in the sample-draw detector. It includes
procedures to prepare for calibration, set the fresh air reading, set the zero reading, and return to
normal operation.
When calibrating the oxygen sensor, calibration gas can be applied at the inlet fitting or at the end
of the inlet line.
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.
Preparing for Calibration
NOTE:
If you can verify a fresh air environment, it is not necessary to use a zero air calibrating
sample to set the fresh air reading at the controller.
1. Follow the instructions in the controller’s operator’s manual for entering calibration mode.
2. Screw the fixed flow regulator into the zero air calibration cylinder.
Setting the Fresh Air Reading
1. Attach the gas bag tubing to the regulator on the zero air calibration cylinder.
NOTE:
A demand flow regulator cannot be used for calibration.
2. Turn the regulator’s on/off knob clockwise to open it. Fill the gas bag.
3. Turn the regulator’s on/off knob counterclockwise to close it.
4. Clamp the gas bag shut and disconnect it from the fixed flow regulator.
5. Connect the gas bag tubing to the inlet line and release the clamp.
6. Allow the sample draw detector to draw sample for one minute.
7. Follow the directions in the controller’s operator’s manual for setting the fresh air reading.
8. Disconnect the gas bag tubing from the inlet line.
9. Empty the gas bag.
10. Unscrew the fixed flow regulator from the zero air calibration cylinder.
Setting the Zero Reading
1. Screw the fixed flow regulator onto the 100% N
2
calibration cylinder.
2. Attach the gas bag tubing to the regulator on the 100% N
2
calibration cylinder.
NOTE:
A demand flow regulator cannot be used for calibration.
3. Turn the regulator’s on/off knob clockwise to open it. Fill the gas bag.
4. Turn the regulator’s on/off knob counterclockwise to close it.
5. Clamp the gas bag shut and disconnect it from the fixed flow regulator.
6. Connect the gas bag tubing to the inlet line and release the clamp.
