Emerson Rosemount 3051 Reference Manual page 96

Section 4: Operation and Maintenance
November 2012
Example
A Range 4 transmitter with model number 3051_CD4 will be used in a differential pressure
application where the static line pressure is 1200 psi (83 bar). The transmitter output is ranged
with 4 mA at 500 inH
To correct for systematic error caused by high static line pressure, first use the following
formulas to determine corrected values for the low trim and high trim.
Low Trim Value
LT = LRV - (S/100 x P/1000 x LRV)
Where:
In this example:
High Trim Value
HT = (URV - (S/100 x P/1000 x URV)
Where:
In this example:
Complete the Sensor Trim procedure as described on
apply the nominal pressure value of 500 inH
trim (LT) value of 506 inH
value.
86
O (1,2 bar) and 20 mA at 1500 inH
2
LT = Corrected Low Trim Value
LRV = Lower Range Value
S = Span shift per specification (as a percent of reading)
P = Static Line Pressure in psi
LRV = 500 inH O (1.24 bar)
2
S = -1.00%
P = 1200 psi
LT = 500 inH O - (-1%/100 x 1200 psi/1000 x 500 inH
2
LT = 506 inH O
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
URV = 1500 inH O (3.74 bar)
2
S = -1.00%
P = 1200 psi
HT = 1500 - (-1%/100 x 1200 psi/1000 x 1500 inH
HT = 1518 inH O
2
O. However, enter the calculated correct lower
2
O with the Field Communicator. Repeat the procedure for the upper
2
Reference Manual
00809-0100-4001, Rev JA
O (3,7 bar).
2
2
O)
2
page 83. In the example above, at step 4,
Operation and maintenance
O)