RKI Instruments 65-2434RK - Manual (Page 16)

12 • 65-2434RK CO Transmitter
3. Use the following formula to determine the correct test points output for the
calibrating sample.
Output (mV) = (calibrating sample/fullscale) X 400 + 100
For example, with a calibrating sample of 50 PPM CO and a fullscale setting of
300 PPM, the correct output is 167 mV.
167 (mV) = (50/300) X 400 +100
4. Place the controller into its calibration program or disable external alarms.
Setting 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. Hold the calibration cup against the CO sensor’s face. Leave the rubber boot and
charcoal filter on the sensor when calibrating. Hold the cup on gently to allow gas to
escape and avoid pressurizing the sensor’s sensing face.
5. Allow the gas to flow for 2 minutes.
6. Verify a reading of 100 mV (± 2mV).
7. If necessary, use the zero pot on the amplifier PCB to adjust the reading to 100 mV (±
2mV).
8. Turn the regulator’s on/off knob clockwise to close it.
9. Remove the calibration cup from the sensor face.
10. Unscrew the regulator from the zero air calibration cylinder.
11. Leave the sample tubing connected to the regulator and the calibration cup.
Setting the Response Reading
1. Screw the regulator into the calibration cylinder. Verify that the calibration gas is
representative of the transmitter’s target gas.
2. Turn the regulator’s on/off knob counterclockwise to open it.
3. Hold the calibration cup against the CO sensor’s face. Leave the rubber boot and
charcoal filter on the sensor when calibrating. Hold the cup on gently to allow gas to
escape and avoid pressurizing the sensor’s sensing face.
4. Allow the gas to flow for 2 minutes.
5. Verify that the reading matches the response reading (± 2mV) you determined earlier.
6. If necessary, use the span pot on the amplifier PCB to adjust the reading to match the
correct response reading.
7. Turn the regulator’s on/off knob clockwise to close it.
8. Remove the calibration cup from the sensor face.
9. Unscrew the regulator from the calibration cylinder.
NOTE: For convenience, leave the components of the calibration kit connected by the
sample tubing.