Trim the Transmitter, Zero Trim | Emerson Process Management 2051

Quick Installation Guide

00825-0100-4101, Rev EA June 2010

Rosemount 2051

STEP 6: TRIM THE TRANSMITTER

NOTE

Transmitters are shipped fully calibrated per request or by the factory default of full scale (span = upper range limit).

Zero Trim

A zero trim is a single-point adjustment used for compensating mounting position effects. When performing a zero trim, ensure that the equalizing valve is open and all wet legs are filled to the correct level.

There are two methods to compensate for mounting effects:

•Field Communicator

•Transmitter Zero Adjustment Buttons

Select the appropriate method and follow instructions below.

Using the Field Communicator

If zero offset is within 3% of URL, follow the “Using the Field Communicator” instructions below. This zero trim will affect the 4-20 mA value, the HART PV, and the display value.

HART Fast Keys	Steps
1, 2, 3, 3, 2	1. Equalize or vent the transmitter and connect Fieldbus communicator.
	2.	At the menu, input the Fast Key sequence.
	3.	Follow the commands to perform a zero trim.

Using the Transmitter Zero Adjustment Buttons

Using the Transmitter Zero Adjustment Buttons, the Lower Range Value (LRV) will be set to the pressure applied to the transmitter. This adjustment will affect the 4-20 mA value only. Perform the following steps to perform a rerange using the zero adjustment buttons.

1.Loosen the certifications label screw and slide the label to expose the zero adjustment buttons. See Figure 9.

2.Set the 4 mA point by pressing the zero button for 2 seconds. Verify that the output is 4 mA. The optional LCD will display ZERO PASS.

Figure 9. Zero and Span buttons

Span

Zero