Emerson Rosemount 1154DH, Справочное руководство

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Reference Manual
00809-0100-4631, Rev BA
April 2007
3-7
Rosemount 1154 Series H
Span
Range Codes 4, 5, and 8:
+0.75% of input/1,000 psi
Range Codes 6 and 7:
+1.25% of input/1,000 psi
The correction procedure below uses the following example:
Range Code 5, calibrated at –100 to 300 inH
2
O to be operated at 1,200 psi
line pressure. Note that steps 3–6 are omitted for ranges based at zero
differential pressure.
1. Calibrate the unit per the “Calibration Procedure” on page 3-2 to
output = 4 mA at –100 inH
2
O and 20 mA at 300 inH
2
O.
2. Calculate correction factor:
3. Calculate zero adjustment correction in terms of pressure:
4. Convert pressure correction to percent of input span:
5. Calculate correction in terms of output span (mA):
6. Add the milliamp correction to the ideal zero output (4 mA). This is the
corrected ideal zero output:
7. Calculate full-scale adjustment correction in terms of pressure:
8. Repeat Step 4 with the results of Step 7:
9. Repeat Step 5 with the result of Step 8:
10. Add the mA correction to the ideal full-scale output (20 mA). This is
the corrected ideal full-scale output.
0.75 %
1,000 psi
------------------------ 1 200 psi 0.9% differential input = ,
×
0.9 % 100 inH
2
–
×
O 0.9 inH
2
O – =
0.9 inH
2
O
–
400 inH
2
O input span
---------------------------------------------------------------- 0.225 % span – =
0.225 % 16 mA span
×
–
0.036 mA
–
=
4.00 mA 0.036 3.964 mA = –
0.9 % 300 inH
2
×
O 2.7 inH
2
O =
2.7 inH
2
O
400 inH
2
O input span
---------------------------------------------------------------- 0.675 % span =
0.675 % 16 mA span
×
0.108 mA =
20.00 mA 0.108 mA 20.108 mA = +