Emerson Net Safety MLP-A-SC1100, User Manual

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Operations Manual
FGD-MAN-0047 January 2017
19
Section 7: Calibrate
7.1 Calibration procedure
The calibration procedure requires about five minutes to complete. If
gas is not applied at the appropriate time, a calibration failure may
occur. Refer to
Calibration failure for specific information.
For accurate performance, the Millennium should be calibrated using
50% span of the specific gas of concern. The concentration of gas,
corresponding to 100% of full scale, is converted to a linear
4–20 mA output signal which can be powered from the primary dc
supply of the instrument. Power up the unit for at least 4 hours BEFORE
the first calibration.
The following calibration procedure should be followed to ensure an
accurate correlation between the 4–20 mA output signal and the gas
concentration.
To compensate for distance when remotely calibrating (sensor wired
for separation), decrease the tubing diameter or increase the
calibration gas flow rate between canister and sensor. Always confirm
calibration by applying gas directly at the sensor.
Figure 7-1 Calibration Procedure