RKI Instruments 65-2516RK - Manual (Page 17)

65-2516RK Oxygen Transmitter • 13
Calibration
This section describes how to calibrate the oxygen transmitter. It includes procedures to
prepare for calibration, set the fresh air reading, set the zero reading, and return to normal
operation. It describes the test using a calibration kit that includes a calibration cup,
calibration gas, sample tubing, and a fixed flow regulator with an on/off knob. RKI
Instruments, Inc. recommends using a 0.5 LPM (liters per minute) fixed flow regulator.
Preparing for Calibration
NOTE: Calibrating the oxygen transmitter may cause alarms. Be sure to put the
controller into its calibration program or disable external alarms before
continuing.
1. Unscrew and remove the junction box cover.
2. Set a voltmeter to measure in the millivolt (mV) range.
WARNING: Do not remove the detector housing cap or junction box cover while the
circuits are energized unless the area is determined to be non-hazardous.
Keep the detector housing cap and junction box cover tightly closed during
operation.
3. Plug the positive lead into the test point labeled TP+; plug the negative lead into the
test point labeled TP-.
4. Screw the calibration cup onto the detector housing.
Setting the Fresh Air Reading
NOTE: If you can verify that the oxygen transmitter is in a fresh air environment, you do
not need to apply zero air to the detector before adjusting the zero reading.
1. Screw the regulator into the zero air calibration cylinder.
2. Use the sample tubing to connect the regulator to the calibration cup.
3. Turn the regulator’s on/off knob counterclockwise to open it.
4. Allow the gas to flow for 2 minutes.
5. Verify a voltmeter reading of 434 mV (±2 mV).
6. If necessary, use a flat-blade screwdriver to adjust the span pot on the amplifier until
the voltmeter reading is 434 mV (±2 mV).
7. Turn the regulator on/off knob clockwise to close it.
8. Unscrew the regulator from the zero air calibration cylinder.
Leave the sample tubing connected to the regulator and the calibration cup.
Setting the Zero Reading
1. Screw the regulator into the 100% nitrogen calibration cylinder.
2. Turn the regulator’s on/off knob counterclockwise to open it.
3. Allow the gas to flow for two minutes and verify a reading of 100 mV (±2 mV).
4. If necessary, use the zero pot on the amplifier to adjust the reading to 100 mV (±2 mV).