GE Optica, Operator'S Manual

Page: 49 / 150

Operation 3-5
January 2006
Scenario 1: Measurement
Without Enabling the
Process Pressure Feature
Process pressure is 100psi, within the range of a typical GE
Infrastructure Sensing chilled mirror sensor. Since vapor pressure and
dew point are pressure-dependent, a flow meter is installed
downstream of the sensor to assure that the sensor cavity is at the
process pressure (see Figure 3-5 below).
Figure 3-5: Measurement Scenario 1
Measuring Vapor Pressure
Without a Pressure Sensor
To measure vapor pressure without a pressure sensor, make the
following entries in the Pressure Input menu section for this example:
•
Input: Use Default
•
Units: psia
•
Default: 100
•
Process Status: Disabled
Measuring Vapor Pressure
With a Pressure Sensor
To measure vapor pressure with a 4-20 mA, 0-30 psia pressure sensor,
connect the sensor to the Optica’s terminal block and make the
following entries in the Pressure Input menu:
•
Input: Iin 4-20
•
Units: psia
•
Upper: 30.00
•
Lower: 0.00
•
Process Status: Disabled
Measuring Dew Point
In this scenario, dew point can be measured without knowledge of gas
pressure. Connect the equipment as shown above, with or without a
pressure sensor, and follow the normal operating procedures.