RKI Instruments 65-2498RK - Manual (Page 13)

65-2495RK/65-2498RK H
2
S Detector • 9
Probable causes
• The plug-in sensor has been replaced and the shorting jumper has not been removed.
• The calibration cylinder is low, out-dated, or defective.
• The incorrect calibration cup or regulator is being used.
• The membrane on the detector housing cap is blocked with dirt or some other
particulate contamination.
• The detector is malfunctioning.
Recommended action
1. Confirm that the shorting jumper on the plug-in sensor pins has been removed.
2. Verify that the calibration cylinder contains an adequate supply of a fresh test sample.
3. Confirm that you are using the correct calibration cup and regulator. See “Parts List”
on page 13 for the required calibration cup and regulator.
4. Check the face of the detector housing cap and remove any particulate contamination
from the hydrophobic membrane if necessary. If the membrane appears saturated
with contamination or damaged, replace the membrane as described in “Replacing
the Hydrophobic Membrane” on page 10.
5. If the calibration/response difficulties continue, replace the plug-in sensor as
described later in this section.
6. If the calibration/response difficulties continue, contact RKI Instruments, Inc. for
further instruction.
Replacing Components of the H
2
S Detector
This section includes a procedure to replace the plug-in H
2
S sensor, one to replace the
hydrophobic membrane, and one to replace the entire H
2
S detector assembly. In most
cases, it is not necessary to replace the entire detector assembly.
Replacing the Plug-in H2S Sensor
CAUTION: The plug-in sensor contains electrolyte which is a dilute acid. Do not disassemble the
sensor when replacing it with a new one. If sensor electrolyte comes in contact with
your skin, wash affected area thoroughly with soap and water.
1. Turn off the controller.
2. Turn off or unplug power to the controller.
3. Unscrew the detector housing cap from the detector housing body.
4. Unplug and remove the old H
2
S sensor.
5. Remove the replacement H
2
S sensor from its packaging and remove the wire jumper
that is shorting the WE and RE sensor pins. This wire jumper is installed on the sensor
pins for shipment or storage but must be removed for the sensor to operate properly
when installed in a detector.
WARNING: The H
2
S sensor will not operate properly if the wire jumper is not removed.
6. Carefully plug the replacement sensor into the four-socket pattern that is located in
the detector housing body.