Calibration; Calibration Overview - Emerson Rosemount 3051S Reference Manual

Reference Manual
00809-0100-4804, Rev AA
January 2011

CALIBRATION

Calibration Overview

P and P Sensor
HI LO
Calibration
3, 4, 3, 1
P Sensor
HI
P Sensor 3, 4, 4, 1
LO
Rosemount 3051S ERS System
Calibrating a 3051S ERS System involves the following tasks:
1. Configure process variables
See "Basic Setup" on page 3-3 for additional details:
• Units of measure
• Damping
• Variable mapping
• 4 and 20 mA range points
• Alarm and saturation levels
2. Calibrate the P and P
HI
Calibrate each pressure sensor by performing a zero/lower and an upper
sensor trim.
3. Differential Pressure zero trim
Perform a zero-trim on the Differential Pressure (DP) reading to establish
a zero-based measurement.
4. Calibrate the 4-20 mA output
Adjust the analog output to match the control loop.
Each pressure sensor in the 3051S ERS System can be individually
calibrated. The calibration trim functions for both pressure sensors can be
accessed by connecting to the entire 3051S ERS System with a field
communicator or AMS as shown in Figure 2-9, Figure 2-10, and Figure 2-11.
While calibrating each pressure sensor is not mandatory, it is recommended
in order to improve the accuracy of the DP calculation.
Zero Trim
A zero trim is a single-point offset adjustment. It is useful for compensating for
mounting position effects and is most effective when performed after the
transmitter is installed in its final mounting position.
NOTE
The pressure reading from the sensor must be within three percent of the true
zero (atmospheric pressure) in order to calibrate with the zero trim function.
A zero trim cannot be performed on an absolute-style pressure sensor. To
correct for mounting position effects on an absolute sensor, perform a lower
sensor trim. The lower sensor trim function provides an offset correction
similar to the zero trim, but it does not require a zero-based input.
To perform a zero trim, follow the procedure below:
pressure sensors
LO
4-3