Rosemount 4088A MultiVariable, Quick Start Manual

Page: 18 / 32

September 2016
18
Quick Start Guide
7.0 Trim the transmitter
Transmitters are shipped fully calibrated per request or by the factory default of
full scale.
Use RTIS with the Rosemount 4088 DTM or a HART Field Communicator with the
Rosemount 4088 Device Descriptor to communicate with and perform
maintenance on the Rosemount 4088 MultiVariable Transmitter.
7.1 Zero trim
A zero trim is a single-point adjustment used for compensating mounting
position and line pressure effects on static and differential pressure sensors.
When performing a zero trim, ensure that the equalizing valve is open and all wet
legs are filled to the correct level.
The transmitter will allow up to 95% of URL zero error to be trimmed through a
lower trim procedure.
If zero offset is less than 5% of URL, follow the user interface software instructions
below.
Performing a zero trim using the Field Communicator
1. Block, equalize, and vent the transmitter and connect the Field Communicator
(for more information on connecting the Field Communicator, see Figure 14
on page 15 ).
2. If the device is equipped with a static pressure sensor, trim the sensor by
inputting the following Fast Key sequence at the 4088 MultiVariable
Transmitter menu:
3. Follow the static pressure trim procedure.

Zero Trim for Gauge Pressure Sensors
OR

Lower Sensor Trim for Absolute Pressure Sensors
Note
When performing a lower sensor trim on an absolute pressure sensor, it is possible to
degrade the performance of the sensor if inaccurate calibration equipment is used. Use a
barometer that is at least three times as accurate as the absolute sensor of the 4088
MultiVariable Transmitter.
4. Zero the differential pressure sensor by inputting the following Fast Key
sequence at the Rosemount 4088 MultiVariable Transmitter menu:
5. Follow the zero DP trim procedure.
Fast Keys Description
3,4,2,8 Static Pressure Sensor Trim Options
Fast Keys Description
3,4,1,8,5 Differential Pressure Sensor Zero Trim