ProSoft Technology MVI56-AFC - Manual (Page 36)

Meter Channel Functionality MVI56-AFC ♦ ControlLogix Platform
User Manual Liquid and Gas Flow Computer
Page 36 of 316 ProSoft Technology, Inc.
February 25, 2011
3.5 Liquid Product Overview
The module supports applications involving crude or refined oil such as crude oil,
oil/water emulsion, propane, butane, NGLs, LPGs, gasoline, jet fuels and
lubricating oils.
When measuring liquids with density correction, density at flowing conditions is
required. This value may be provided directly as a process input, or the module
can calculate a density from the frequency provided by a densitometer device.
3.5.1 To use a densitometer
Follow the steps below to use a densitometer.
1 Configure it, entering all configuration parameters directly from the calibration
data sheet supplied by the densitometer manufacturer.
2 Supply the frequency output from the densitometer in Hz as a floating-point
value in the "Flowing density" process-input location over the backplane
(refer to the Backplane Communication section for your platform in the
MVI56-AFC manual to determine the correct location). The AFC then
calculates a flowing density value, which is then validated by the range check
mandated by the "Density" values of "Process Input Scaling" of the meter
configuration. The "Scaling" sub-selection is not used against the frequency
input, however; the frequency is always input as floating-point.
Note: If using the Densitometer feature, select the Density Process Input Scaling for 4 to 20mA
and enter the densitometer frequency as a floating-point value.
3.5.2 Module Configuration
3.5.3 Density Units
The liquid density units can be expressed as:

Density is in kg/m
3

Relative density 60ºF/60ºF

API gravity
3.5.4 Measuring Water Diluent
For liquid measurement applications, the optional automatic calculation of Net Oil
Volume and mass based on the Sediment and Water (S&W) percent input is
supported. Only provide the S&W percent value in the specified controller
register. The module puts the gross standard (or gross clean oil), net oil and
water accumulations in separate accumulators. Refer to Net Accumulator
Calculation (page 89).