RKI Instruments 65-2424RK - Manual (Page 16)

12 • 65-2424RK H
2
S Transmitter
Setting the Zero Reading
NOTE If you can verify that the H
2
S transmitter is in a fresh air environment, you do not
need to apply zero air to the detector before adjusting the zero reading.
1. Turn the regulator on/off knob counterclockwise to open it.
2. Hold the calibration cup against the H
2
S sensor’s face. Leave the rubber boot and
sealing spacer on the sensor when calibrating. Hold the cup on gently to allow gas to
escape and avoid pressurizing the sensor’s sensing face.
3. Allow the gas to flow for 2 minutes.
4. Verify a reading of 100 mV (± 2mV).
5. If necessary, use the zero pot on the amplifier PCB to adjust the reading to 100 mV
(± 2mV).
6. Turn the regulator on/off knob clockwise to close it.
7. Remove the calibration cup from the sensor face.
8. Unscrew the regulator from the zero air calibration cylinder.
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 on/off knob counterclockwise to open it.
3. Hold the calibration cup against the H
2
S sensor’s face. Leave the rubber boot and
sealing spacer 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 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.
Returning to Normal Operation
1. Remove the voltmeter leads from the amplifier test points.
2. Secure the cover to the enclosure.
3. When the display reading falls below the alarm setpoints, return the controller to
normal operation.
4. Verify that the controller display reading decreases and stabilizes at 0 ppm H
2
S.