Calibration Overview; Calibration Considerations - Emerson Rosemount 2151N Reference Manual

Reference Manual
00809-0000-4851 Rev AD
December 2023

CALIBRATION OVERVIEW

Calibration Considerations

Calibration
Process leaks could result in death or serious injury.
Install and tighten all four flange bolts before applying
•
pressure.
Do not attempt to loosen or remove flange bolts while
•
the transmitter is in service.
Replacement equipment or spare parts not approved by
Rosemount Nuclear for use could reduce the pressure
retaining capabilities of the transmitter and may render the
instrument dangerous.
• Use only components supplied with the 2151N
transmitter or designated by Rosemount Nuclear as
spare parts for the 2151N.
NOTE
The pressure unit "inches H
throughout this section. For ease of reading this pressure unit
will be abbreviated to "inH
Review this section to become familiar with the fundamentals
of calibrating the Rosemount 2151N transmitter. Contact
Rosemount Nuclear with questions regarding calibrations that
are not explained in this manual.
Rosemount 2151N transmitters are factory calibrated to the
range shown on the nameplate (see Figure 1-1). This range
may be changed within the limits of the transmitter. Zero may
also be adjusted to elevate (for all models except absolute
pressure reference) or suppress (for all models). Calibrations
that have a lower range value below zero are termed zero
elevated while calibrations that have a lower range value
above zero are termed zero suppressed.
NOTE
Transmitters are factory calibrated at ambient temperature
and pressure to the customer's specified range. If calibration
is not specified, transmitters are calibrated 0 to Upper Range
Limit (URL).
The zero and span are adjusted during calibration using zero
and span adjustment screws. 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).
Transmitter output increases with clockwise rotation of the
adjustment screws. For normal calibration adjustments, the
zero adjustment screw has negligible effect on the span and
the span adjustment has negligible effect on the zero.
Rosemount 2151N
WARNING
WARNING
O at 68ºF (20ºC)" is used
2
O".
2
20