Controlotron 1010PVDN, Полевой руководство

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2-17
1010PVNFM-3A
Section 2
Setting The Pressure Slope
The 1010PVN 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 pressure (4.7 PSIA/1.013 Bara) 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 tempera-
ture vary.
The 1010PVN has the ability to accept a 4-20 mA input for pressure. If used, the 1010PVN 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:
l
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).
l
Use the following formula to calculate the Pressure Slope Factors with the Liquid Class:
Pressure Slope Factor = (Vs @Pmin) - (Vs @Pmax)
(Pmin - Pmax)
l
Calculate the average of all the Pressure Slope Factors within the Liquid Class.
To enter the Pressure Slope Factor:
From the [Liquid Table] menu cell, press to scroll down to Pressure Slope .
Press to enable numeric entry.
Use the keypad numeric keys to enter the desired Pressure Slope Factor.
To enter the Pressure Slope Factor press .
This moves the highlight down to [Liquid Index].
The Reference Base Temperature
The 1010PVN uses a reference Base Temperature of 60ºF (15.6ºC) for the LiquIdent™ Slope,
14.7 PISA (1.013 Bara) Pressure Slope and other settings.
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