Emerson SC311 Reference Manual page 10

Reference Manual
MAN-0091, Revision 8
In order to ease the calibration process a calibration cup (CCS-1) can be attached to the bottom of the
sensor housing and calibration tubing run from the calibration cup to a convenient place for applying
the calibration gas, eliminating the need to access the sensor directly. In this case, to compensate for
the effect of distance, consider decreasing the calibration tubing length to some length where the end
of the tubing to the gas canister is still accessible or increase the calibration gas flow rate between the
calibration gas cylinder and sensor. Refer to Figure 2-1 for an example of the sensor separation. For
tubing lengths less than 10 feet (3 meters), use a 0.5 LPM regulator and for lengths greater than 10 feet
(3 meters) use a 1.0 LPM regulator. On initial install, always confirm readings directly at the transmitter
by applying a known gas concentration to the sensor and compare the output from the transmitter.
Readings should be accurate to the gas concentration applied taking into account the sensor accuracy
specifications in
Figure 2-1 Sensor separation example
Installation
Section 7.2.2.
Millennium II Transmitter
Conduit
Separation Junction Box
Millennium II SC311 Sensor
CCS-1 Calibration Cup
Calibration Tubing
Installation
June 2016
3