User guide
65-2615RK-05-04 M2 Transmitter Operator’s Manual 30
10. If external alarms have been disabled, enable them when the display returns to a 
normal fresh air reading.
11. Store the components of the calibration kit in a safe place.
Quarterly
Calibrate the M2 as described in “Calibration” on page 33. See “Calibration Frequency” 
on page 32 for a discussion of calibration frequency guidelines.
Troubleshooting
The troubleshooting guide describes symptoms, probable causes, and recommended 
action for problems you may encounter with the M2.
NOTE: This troubleshooting guide describes M2 problems only. If the M2 is connected to 
a controller, see the controller operator’s manual for problems you may 
encounter with the controller.
Table 7:Troubleshooting the Hydrogen Sulfide Detector
Condition Symptom(s) Probable Causes Recommended Action
No Power The display backlight 
is off and the display 
screen is blank.
• The power wiring is 
disconnected or 
misconnected.
• The display cable is 
disconnected or 
misconnected.
1. Verify that the wiring to the 
power source or controller is 
correct and secure.
2. Verify that the ribbon cable 
connecting the terminal PCB to 
the control PCB is securely 
installed. This ribbon cable plugs 
into a connector on the top edge 
of the control PCB and on the 
bottom of the terminal PCB.
3. If the power difficulties continue, 
contact RKI for further 
instruction.
Frequent or 
Suspect 
Alarms
The M2 alerts you to 
frequent or suspect 
alarms while the 
fresh air readings 
remain on zero.
•The M2 is 
experiencing false 
readings due to RFI 
or EMI.
• The detector wiring 
is disconnected, 
misconnected, or 
intermittent.
1. Verify that the M2 wiring is 
properly shielded. See “Wiring 
the M2 Transmitter” on page 12.
2. Verify that the detector wiring is 
correct and secure.
3. Increase the alarm on delay 
setting in Configuration Mode.
4. If the frequent or suspect alarm 
difficulties continue, contact RKI 
for further instruction.










