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Reference Manual
00809-0100-4102, Rev AA
Section 5: Operation and Maintenance
May 2013
Operation and maintenance
Zero Effect:
± 0.1% of the upper range limit per 1000 psi (69 bar) for line pressures from 0 to 2000 psi (0 to
138 bar)
For line pressures above 2000 psi (138 bar), the zero effect error is ± 0.2% of the upper range
limit plus an additional ± 0.2% of upper range limit error for each 1000 psi (69 bar) of line
pressure above 2000 psi (138 bar).
Example: Line pressure is 3000 psi (3 kpsi). Zero effect error calculation:
± {0.2 + 0.2 x [3 kpsi - 2 kpsi]} = ± 0.4% of the upper range limit
Span Effect:
Correctable to ±0.2% of reading per 1000 psi (69 bar) for line pressures from 0 to 3626 psi (0 to
250 bar)
The systematic span shift caused by the application of static line pressure is -1.00% of reading
per 1000 psi (69 bar) for Range 4 transmitters, and -1.25% of reading per 1000 psi (69 bar) for
Range 5 transmitters.
Use the following example to compute corrected input values.
Example
A transmitter with model number 2051_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
2
O (1,2 bar) and 20 mA at 1500 inH
2
O (3,7 bar).
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.
LT = LRV + S x (LRV) x P
HT = URV + S x (URV) x P
In this example:
Where: LT = Corrected Low Trim Value
LRV = Lower Range Value
S = –(Span shift per specification)
P = Static Line Pressure
Where: HT = Corrected High Trim Value
URV = Upper Range Value
S = –(Span shift per specification)
P = Static Line Pressure
URV = 1500 inH
2
O (3.74 bar)
LRV = 500 inH
2
O (1.25 bar)
P = 1200 psi (82.74 bar)
S = ± 0.01/1000