Calibration Procedures; Span And Zero Adjustment; Zero Based Calibration Procedure (Lrv Is Zero) - Emerson Rosemount 2151N Reference Manual

Reference Manual
00809-0000-4851 Rev AD
December 2023
CALIBRATION
PROCEDURES

Span and Zero Adjustment

Zero Based Calibration Procedure
(LRV is zero)
Figure 3-4 – Zero Based Calibration
Example
Figure 3-4a – Example for Zero Based
Calibration (English Units)
Calibration
The following calibration procedures describe the
recommended steps necessary to calibrate the Rosemount
2151N pressure transmitter.
The 2151N pressure transmitter contains electronic circuit
boards which may be static sensitive.
NOTE
Electronics housing covers do not need to be removed to
access the zero and span adjustment screws.
NOTE
The pressure unit "inches H
throughout this section. For ease of reading this pressure unit
will be abbreviated to "inH
The adjustment screws are accessible externally and are
located behind the access cover plate on the side of the
electronics housing (see Figure 3-1). The transmitter output
increases with clockwise rotation of the adjustment screw.
The coarse zero select jumper is in the Nominal position for all
zero based calibrations.
1. Apply a pressure equal to the LRV to the high side
pressure connection and turn Zero adjustment until
output reads 4 mA.
2. Apply a pressure equal to the URV to the high side
process connection and turn Span adjustment until
output reads 20 mA.
3. Check to assure desired outputs are achieved and
repeat steps 1 and 2 if necessary.
Figure 3-4 contains an example of calibrating a transmitter
with a zero based calibration. Figure 3-4a uses English Units
(inH2O) while Figure 3-4b uses SI Units (kPa).
Range 2 for a calibration of 0 to 100 inH
span)
1. Adjust the zero: With 0 inH
transmitter, turn the Zero adjustment until the
transmitter reads 4 mA.
2. Adjust the span: Apply 100 inH
high side connection. Turn the Span adjustment until
the transmitter output reads 20 mA.
3. Check to assure desired outputs are achieved and
repeat steps 1 and 2 if necessary.
Rosemount 2151N
CAUTION
O at 68ºF (20ºC)" is used
2
O".
2
O (100 inH
2
O applied to the
2
O to the transmitter
2
O
2
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