Definitions - Emerson Rosemount 2151N Reference Manual

Rosemount 2151N

Definitions

21
For large amounts of zero adjustment, a coarse zero select
jumper is provided. The jumper is located on the electronics
assembly, accessible within the electronics housing as shown
in Figures 3-1 and 3-2. Models ordered with optional output
damping will have a damping adjustment potentiometer
located on the amplifier board (see Figure 3-2).
Procedures for calibration, including setting the coarse zero
select jumper and optional damping adjustment, are provided
later in this section.
The following definitions and descriptions are provided to aid
in calibration:
DP
Differential pressure between the high pressure "H" and low
pressure "L" process inputs, as marked on the transmitter
module.
Upper Range Limit (URL)
The highest pressure the transmitter can be adjusted to
measure, specified in the model ordering information by
pressure range code.
Upper Range Value (URV)
The highest pressure the transmitter is adjusted to measure.
This pressure corresponds to the 20mA output point.
Lower Range Value (LRV)
The lowest pressure the transmitter is adjusted to measure.
This pressure corresponds to the 4mA output point.
Span = |URV - LRV|
Zero Based Calibration
Calibration where the LRV is zero (see Figure 3-3)
Elevated Zero Calibration
Calibration where the LRV is less than zero (i.e. the LRV is
achieved when a positive pressure is applied to the low
pressure side of the DP cell or a vacuum is applied to the high
pressure side of the DP cell – see Figure 3-3).
Suppressed Zero Calibration
Calibration where the LRV is greater than zero (i.e. the LRV is
achieved when a positive pressure is applied to the high
pressure side of the DP cell or a vacuum is applied to the low
pressure side of the DP cell – see Figure 3-3).
Reference Manual
00809-0000-4851 Rev AD
December 2023
Calibration