Emerson Rosemount 3051 Reference Manual page 88

Operation and maintenance
August 2019
to optimize transmitter performance by reducing the effect of static line pressure in these
applications. The Rosemount 3051 Differential Pressure Transmitters (ranges 0 through 3)
do not require this procedure because optimization occurs at the sensor.
The systematic span shift caused by the application of static line pressure is –0.95 percent
of reading per 1000 psi (69 bar) for Range 4 transmitters and –1% of reading per 1000 psi
(69 bar) for Range 5 transmitters. Using the following procedure, you can correct the span
effect to ±0.2 percent of reading per 1000 psi (69 bar) for line pressures from 0 to 3626 psi
(0 to 250 bar).
Use the following example to compute correct input values.
Example
A Range 4 differential pressure HART
application with a static line pressure of 1200 psi (83 bar). The transmitter output is
ranged with 4 mA at 500 inH
systematic error caused by high static line pressure, first use the following formulas to
determine the corrected values for the high trim value.
High trim value
HT = (URV – [S/100 ×P/1000 × LRV])
Where:
In this example:
URV =
S =
P =
LT =
LT =
Complete the upper sensor trim procedure as described in
example above, when calculating the stability per month, apply the nominal pressure
value of 1500 inH
1517.1 inH
Note
The range values for the 4 and 20 mA points should be at the nominal URV and LRV. In the
example above, the values are 1500 inH
on the HOME screen of the Field Communicator. Modify, if needed, by following the steps
in Rerange the
88
O (1,2 bar) and 20 mA at 1500 inH
2
HT = Corrected high trim value
URV = Upper range value
S = Span shift per specification (as a percent of reading)
P = Static Line Pressure in psi
1500 inH O (3.74 bar)
2
–0.95%
1200 psi
1500 – (–0.95%/100 × 1200 psi/1000 psi × 1500 inH
1517.1 inH O
2
O Lo. However, enter the calculated correct upper sensor trim value of
2
O with a Field Communicator.
2
transmitter.
®
transmitter (Rosemount
O)
2
Perform a sensor
O and 500 inH O respectively. Confirm the values
2 2
Reference Manual
00809-0100-4007
™
3051 CD4...) is used in an
O (3,7 bar). To correct for
2
trim. In the
Rosemount 3051