00809-0100-4835 Rev BD
3-14
High Static Line Pressure Span
Correction for Range Code 4 and 5
DP Transmitters (continued)
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 3-2 divided by 100
LRV = Lower Range Value
URV = Upper Range Value
P = Static Line Pressure
Span = Calibrated Span
Figures 3-9 and 3-10 outline two examples of calculating a High
Static Line Pressure Span Correction using Method 2.
“Example 1” in Figure 3-9 contains a calculation for a Zero Based
Calibration Range. Figure 3-9a uses English units (psi) for the
calculation while Figure 3-9b uses SI units (MPa)
“Example 2” in Figure 3-10 demonstrates the calculation for a Zero
Elevated Calibration Range. “Example 2” can also be followed for
Zero Suppressed Calibration Ranges. Figure 3-10a uses English
units (psi) while Figure 3-10b uses SI units (MPa).