User Manual

65-2516RK Oxygen T r ans mi tter • 13
Calibration
This section describes how to calibrate the oxygen transmitter. It in cludes procedures to
prepare for calibration, s et the fresh air r eading, set the zero reading, and return to normal
operation. It describes the test using a cal i bration 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 Calibrat ion
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 housi ng cap or junctio n bo x cover while the
circuits are energized unless the area is determined to be non-hazardous.
Keep the detector housing cap an d ju nction box cover tightly cl osed during
operation.
3. Plug the positive lead into the test poin t labeled TP+; plug the ne gative 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 f res h air envir onment, 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 samp le 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 volt meter readin g of 434 mV (±2 mV).
6. If necessary, use a flat-blade screwdriver to ad just the span pot on the amplifier unt il
the voltmeter reading is 434 mV (±2 mV).
7. Turn the regulator on/off knob clockwi se to close it.
8. Unscrew the regulator from the zero air calibrati on cylinder.
Leave the sample tubing conn ect ed to the regulator and th e 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).