Gas Detector Response Adjustment - Emerson MRLDS-250 User Manual

SUPPORT CENTER ADVISORY

2. Gas Detector Response Adjustment

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c. Expose the gas detector to gas from the cylinder. Monitor the LED display
reading and check the outputs functions.
Adjusting gas detector response exposes the gas detector to a calibration gas as well
but additionally sets the actual gas detector response level to ensure that the gas
detector activate on the specified gas concentration. This is done via configuring P.-
17 parameter.
Adjustment using calibration gas requires cylinder with the appropriate gas and
concentration. Note that a calibration kit if offered, should consist of a calibration gas
cylinder and a flow regulation valve with flexible non-absorbent tubing.
Steps on how to do Adjustment using Calibration Gas:
Connect the regulator to the test gas port using 3 mm or 1/8" inside diameter
a.
tubing.
b. Activate parameter P.-17 Gas Test Mode. The gas detector will report 0 PPM if
the calibration gas is off; otherwise, it will report the real-time gas concentration in
PPM. NOTE: The analog outputs, relay activity, and PPM reporting are
suspended in Gas Test Mode to prevent false alarms.
c. Expose the gas detector to gas from the cylinder. Monitor the 4-digit LED display
reading.
d. Wait for the PPM reading to stabilize. This should take approximately 4-6
minutes. Minor changes (less than 5 PPM in 10 seconds) are considered stable
readings. Compare the response value with the calibration gas concentration.
e. Adjust the gas detector displayed value by using the UP or DOWN buttons to
increase or decrease the value shown. Adjust until the reading is within ± 2% of
the calibration gas. For example, if the calibration gas is 1000 PPM, the gas
detector is adjusted properly when the displayed reading is between 980 and
1020 PPM.
f. Press the Enter button to store the new adjustment. Turn off the calibration gas
and remove the tubing from the calibration port. If no further changes to the other
Parameters are required, press and hold the information button for 5 seconds to
exit the Parameter list
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