Emerson Rosemount 2151N Reference Manual page 43

Reference Manual
00809-0000-4851 Rev AD
December 2023
Figure 3-9b – Example for High Static Line
Pressure Span Correction using Method 1
(SI Units)
Calibration
Range 4 for a calibration of –0,07 to 0,31 MPa corrected
for 10,34 MPa static line pressure:
1. Calculate the corrected output reading at LRV
= 4 mA + ((0,01 X 10,34 MPa/6,90 MPa X (-0,07
MPa))/0,38 MPa) X 16 mA
= 3,956 mA
2. Calculate the corrected output reading at URV
= 20 mA + ((0,01 X 10,34 MPa/6,90 MPa X 0,31
MPa)/0,38 MPa) X 16 mA
= 20,196 mA
3. At atmospheric static line pressure, apply 0,07 MPa to
the low side process connection (-0,07 MPa), and
adjust the zero until the transmitter output reads 3,956
mA.
4. Remaining at atmospheric static line pressure, apply
0,31 MPa to the high side process connection and
adjust the span until the transmitter output reads
20,196 mA.
5. Check to assure desired outputs are achieved and
repeat steps 3 and 4 if necessary.
When the transmitter is exposed to 10,34 MPa static line
pressure, within specified uncertainties, the output will be 4
mA at -0,07 MPa and 20 mA at 0,31 MPa.
Method 2 for High Static Line Pressure, Ranges 4 and 5
Adjust transmitter pressure input while leaving the output at 4
mA and 20 mA. Use one of the following formula sets
(depending on the pressure units being used to calibrate):
If using English Units (psi):
Corrected LRV pressure input =
Desired LRV – ((S X LRV) X (P/1000))
Corrected URV pressure input =
Desired URV – ((S X URV) X (P/1000))
If using SI Units (MPa):
Corrected LRV pressure input =
Desired LRV – ((S X LRV) X (P/6,90))
Corrected URV pressure input =
Desired URV – ((S X URV) X (P/6,90))
Where:
S = Value from Table 3-1 divided by 100
LRV = Lower Range Value
URV = Upper Range Value
P = Static Line Pressure
Span = Calibrated Span
Rosemount 2151N
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