Emerson Net Safety MLP-A-SC1100, User Manual, Page: 30 / 56

Operations Manual
January 2017 FGD-MAN-0047
20
7.2 Steps in calibration procedure
Refer to Remote calibration if remote calibration is to be performed.
1. Confirm successful power up of controller—LED green blip/blink
every two seconds; no fault indicated.
2. Flow certified clean air at a rate of 0.5 liters per minute through
the calibration cup for 1 minute to ensure clean air environment.
3. Press and hold the Calibration button or use the reed switch to
access the main menu and wait for countdown (10 to 0) to
complete.
4. When Calibrate Sensor YES? displays, use the Calibration button or
reed switch to select YES?. Selection will be confirmed by a
flashing YES.
5. The prompt Methane YES? will display. If calibrating for methane,
use the Calibration button or use the reed switch to select;
otherwise (for another target LEL gas), ignore and wait for the next
prompt.
The purpose of the prompt Methane YES? is for activating the
sensor life feature for methane gas only.
6. When Apply Clean Air displays, apply clean air.
7. Wait for Apply 50% Span Gas to display and apply specific LEL (Air
balanced) gas at a rate of 0.5 liters per minute (use 1.0 liter per
minute for remote calibration).
8. The display will show Calibrating as gas is detected.
9. Remove span gas when the message Remove Gas displays (status
LED green solid and 3.6 mA output).
10. The message Cal Complete will display when calibration is
completed.
11. Apply clean air again to purge system.
Always apply test gas after calibration to verify operation.
7.3 Remote calibration
The preferred tubing has an inside diameter of 3/16 inches; stainless
steel tubing is excellent; plastic tubing is good. Within 10 ft./35 m, a
flow rate of 0.5 liters per minute can be used, but 1.0 litre per minute is
recommended. Always use 1.0 liter per minute for distances
(calibration tube lengths) between10 ft. and 100 ft. Contact Emerson if
a remote calibration distance is greater than 100 ft/30 m is required.
7.4 Abort calibration
The calibration procedure can be aborted. When the display shows
Apply 50% Span Gas, press and hold the reed switch or Calibration
Button until the countdown 10-0 Abort Calibration completes, after
which, the display shows Cal. Complete and then returns to 00 %LEL.
7.4.1 Sensor life check
Units, calibrated for methane only, indicate life expectancy of the
sensor. Once calibration is complete, one of the following messages
may display if the sensor needs replacing.
Sensor near end-of-life
Indicates the sensor will reach end of life before the next calibration can
be completed. Replace sensor as soon as possible. Press the Calibration
button or use the reed switch to clear this message.
End of sensor life, replace sensor
Indicates sensor has reached end of life and needs to be replaced
immediately. Press the Calibration button or use the reed switch to
clear this message. The unit will remain in Fault mode until the sensor is
replaced.