Honeywell SMV 3000 - Manual (Page 188)

176 SMV 3000 Transmitter User’s Manual 1/99
C.2 Standard Flow Equation
Standard Flow
Compensation
(Kuser Model) The Standard Flow Equation (Kuser Model) allows automatic calculation
of the Kuser value that is used to configure PV4 flow variable for SMV
3000. The Kuser value is a scaling factor, based on the dynamics of your
process, which is used to adjust the flow rate to the desired process
parameters, such as
•
dimensional units
•
density
•
pressure
•
temperature.
The standard flow model uses an empirical method to configure PV4 flow
variable for the following primary elements:
•
orifice plates
•
Venturis
•
nozzles
•
averaging pitot tubes
•
and other flow elements with outputs proportional to DP .
The standard flow model can be used to calculate PV4 for volumetric and
mass flow rates for gas, liquid, and steam at standard conditions. A flow
equation for steam mass is also available which compensates for density
based on the ASME steam tables
NOTE: Use the dynamic flow compensation model for increased flow measurement
accuracy. See Subsection C.3.
Standard Flow
Equation
Configuration
Examples The following pages contain two examples for configuring the SMV PV4
output using the Flow Compensation Wizard in the SCT 3000
configuration program. The configuration examples show how to navigate
through the wizard program and enter values to configure the SMV PV4
flow variable for a given flow application. Examples for the following
applications are presented:
•
Air through a Venturi meter
•
Superheated Steam
The standard (Kuser) model wizard in the SCT 3000 is started from the
Equation Model page of the Flow Compensation Wizard.
Continued on next page