Siemens SITRANS FUH1010, Product Instruction Manual, Page: 86 / 264

Functions
7.1 Setting Liquid Parameters
FUH1010 IP65 NEMA 4X Precision Volume
Operating Instructions, 01/2013, A5E32122003-AA
85
Setting the Pressure Slope
The flow meter measures and reports the flowing liquid’s sonic velocity (Vs) and its related
pressure (P). Since a pressure change will affect the sonic velocity of the liquid, a method to
balance the measured sonic velocity to a fixed reference temperature (15.6ºC/60ºF) default)
is provided. The Pressure Slope Factor default is 0.030 (m/s per PSI). This pressure slope
factor helps maintain an accurate liquid identification as the LiquIdent factor and liquid
temperature vary.
The flow meter has the ability to accept a 4-20 mA input for pressure. If used, the flow meter
will process pressure data based on the analog input. This is recommended for pipelines that
have wide pressure variances.
To calculate a liquid's Pressure Slope Factor:
1. Establish the maximum (Pmax) and minimum (Pmin) pressures for all liquids within the
Liquid Class. For each liquid, note the measured sonic velocity at Pmax and the sonic
velocity at Pmin (in-meters-per-second).
2. Use the following formula to calculate the Pressure Slope Factors with the Liquid Class:
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V
#
3
PLQ
9
V
#
3
PD[
3
PLQ
3
PD[
3. Calculate the average of all the Pressure Slope Factors within the Liquid Class.
To enter the Pressure Slope Factor
1. From the [Liquid Table] menu cell, press <Up/Down> Arrow> to scroll down to [Pressure
Slope].
2. Press <Right Arrow> to enable numeric entry.
3. Use the keypad numeric keys to enter the desired Pressure Slope Factor.
4. To enter the Pressure Slope Factor press <ENTER>.
5. This moves the highlight down to [Base Temperature].
Setting the Base Reference Temperature
The flow meter uses a reference Base Temperature of 15.6ºC (60ºF) for the LiquIdent
calculation and Standard Volume compensation. Any temperature can be entered and used
as the reference Base Temperature (e.g., 20ºC/68ºF).
To enter the Base temperature:
1. From the [Liquid Table] menu cell, press <Up/Down Arrow> to scroll down to [Base
Temperature].
2. Press <Right> to enable numeric entry.
3. Use the keypad numeric keys to enter the desired Base Temperature.
4. To enter the Base Temperature press <ENTER>.