52
Reference Manual
00809-0100-4108, Rev BA
Section 5: Operation and Maintenance
March 2014
Operation and maintenance
5.3
Recommended calibration tasks
Table 5-1. Basic and full calibration tasks
5.4
Calibration overview
The Rosemount 2088 Pressure Transmitter is an accurate instrument that is fully calibrated in
the factory. Field calibration is provided to the user to meet plant requirements or industry
standards. Complete calibration of the Rosemount 2088 can be split into two halves: Sensor
Calibration and Analog Output Calibration.
Sensor Calibration allows the user to adjust the pressure (digital value) reported by the
transmitter to be equal to a pressure standard. The Sensor Calibration can adjust the pressure
offset to correct for mounting conditions or line pressure effects. This correction is
recommended. The calibration of the pressure range (pressure span or gain correction) requires
accurate pressure standards (sources) to provide a full calibration.
Like the Sensor Calibration, the analog output can be calibrated to match the user measurement
system. The Analog Output Trim (4-20mA/ 1-5 V Output Trim) will calibrate the loop at the 4mA
(1 V) and 20mA (5 V) points.
The Sensor Calibration and the Analog Output Calibration combine to match the transmitter’s
measurement system to the plant standard.
Absolute pressure transmitters (Rosemount 2088A) are calibrated at the factory. Trimming
adjusts the position of the factory characterization curve. It is possible to degrade
performance of the transmitter if any trim is done improperly or with inaccurate
equipment.
Field installation tasks
Bench calibration tasks
1.
Perform Sensor zero/lower Trim:
Compensate for mounting pressure
effects
a.
Refer to
Section 3.5
for manifold
operation instructions to properly
drain/vent valves
2.
Set/check basic configuration
parameters
a.
Output units
b.
Range points
c.
Output type
d.
Damping Value
1.
Perform optional 4-20mA 1-5 Vdc
Output Trim
2.
Perform a Sensor Trim
a.
Zero/lower trim
page 64
using line
pressure effect correction.
Reference
Section 3.5
for
manifold drain/vent valve
operation instructions.
b.
Optional full scale trim. Sets the
span of the device and requires
accurate calibration equipment
c.
Set/check basic configuration
parameters.
