16 • 65-2330RKSS H
2
S Transmitter
Replacing Components of the H
2
S Transmitter
This section includes a procedure to replace the H
2
S plug-in sensor, the entire detector
assembly, the hydrophobic membrane, and the amplifier. In most cases, it is not necessary to
replace the entire detector assembly.
Replacing the Plug-In H
2
S Sensor
CAUTION:
The 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. Make sure not to lose
the cap gasket.
4. Unplug and remove the H
2
S sensor.
5. Remove the replacement sensor from its packaging and remove the wire jumper. 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.
Slow or No
Response/
Difficult or
Unable to
Calibrate
• Unable to accurately
set the zero or
response reading
during calibration.
• Transmitter requires
frequent calibration.
Note:
Under
“normal”
circumstances, the
transmitter requires
calibration once every
3 months.
Some applications
may require a more
frequent calibration
schedule.
• The calibration
cylinder is low, out-
dated, or defective.
• The hydrophobic
membrane in the
detector housing cap
is wet or clogged
with dirt or other
particulates.
• The calibration gas
is not an appropriate
concentration.
• The transmitter is
malfunctioning.
1. Verify that the calibration cylinder
contains an adequate supply of a
fresh test sample.
2. 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
the next section.
3. Verify that the calibration gas
concentration is appropriate for the
transmitter. Zero emission air (20.9%
oxygen) is normally used for a zero
adjustment if the environment is
suspect and 25 PPM H
2
S in nitrogen
is normally used for a span
adjustment.
4. If the calibration/response difficulties
continue, replace the plug-in sensor
as described later in this section.
5. If the calibration/response difficulties
continue, contact RKI for further
instruction.
Condition
Symptom(s)
Probable Causes
Recommended Action
