CiDRA GVF-100 Gas Volume Fraction Monitoring System - Manual (Page 84)

Copyright © 2006 CiDRA Corporation Page 10-10
20639-01 Rev 03
•
Sensor 1 & 2
- ‘Units’ allows for setting the sensor units to ‘None’ (not used) ‘F’
(temperature degrees F), ‘C’ (temperature degrees C), ‘Barg’
(pressure in Bars gauge), ‘kPag’ (pressure in kilo Pascals gauge),
‘PSIg’ (pressure in pounds per square inch gauge). Note: If an
“absolute” scaled pressure transducer is used select ‘None’ for units.
- ‘Scale’ allows for setting the range of the input in units of measure
(‘Units’) per mA.
- ‘Offset’ allows for inputting an offset in mA due to a non-zero
milliamp sensor output range. The offset is calculated by the equation
y=mx+b where: y is a value within the transducer range, m is the
transducer range divided by the milliamp output range, x is the
milliamp output at the ‘y’ value, and b is the offset.
For example, a 0-100 psig pressure transducer with a 4-20 mA output
will have a –25 offset.
y=mx+b
100 psi = (100psi / 16mA) x (20 mA) +b
100 psi – 125 psi = b
-25 psi = b = ‘Offset’
10.1.4 Customize Menu
The Customize menu is used to configure the transmitter to meet user
needs for local display of flow parameters.
•
Display
The display parameters are used to customize the displayed units and
appearance of the display.
- ‘Line 1’ and ‘Line 2’ adjustments set the outputs of those lines to
‘GVF’, ’SOS’, and ‘Blank’.
- ‘Contrast’ is used to adjust the screen appearance due to lighting
conditions. Normally this is set to 170.
•
Sensor Setup
- ‘State’ – used to turn individual sensors ‘On’ or ‘Off’. Normal
operating condition is with all sensors set to ‘On’.
•
SOS Units
The menu selectable SOS Units are ‘ft’ (feet) and ‘m’ (meter). The
units of time measure are fixed to be in seconds. Hence, the output of
SOS is in units of ‘ft/s’ or ‘m/s’.
•
Wr Protect Mode
When this is ‘Enabled’ no other parameters can be changed. The
user must ‘Disable’ this option before making any menu changes.
Default is ‘Disable’.