Emerson manual Rosemount 3051N, Reference Manual, 00809-0100-4808,Rev CA June

Reference Manual

00809-0100-4808, Rev CA June 2008

Rosemount 3051N

FIGURE 2-6. Local Zero and Span Adjustments.

To rerange the transmitter using the span and zero buttons, perform the following procedure:

1.Loosen the screw holding the label on top of the transmitter housing, and rotate the label to expose the zero and span buttons (see Figure 2-6).

2.Using a pressure source with an accuracy three to ten times the desired calibrated accuracy, apply a pressure equivalent to the lower range value to the high side of the transmitter.

3.To set the 4 mA point, press and hold the zero button for at least two seconds, then verify that the output is 4 mA. If a meter is installed, it will display ZERO PASS.

4.Apply a pressure equivalent to the upper range value to the high side of the transmitter.

5.To set the 20 mA point, press and hold the span button for at least two seconds, then verify that the output is 20 mA. If a meter is installed, it will display SPAN PASS.

NOTE

If the transmitter security jumper is in the ON position, or if the local zero and span adjustments are disabled through the software, you will not be able to make adjustments to the zero and span using the local buttons. Refer to Figure 2-1for the proper placement of the transmitter security jumper. Or refer to “Local Span and Zero Control (Local Keys)” in Section 2 for instructions on how to enable the span and zero buttons.

Span and Zero Adjustment Buttons

After you rerange the transmitter using the span and zero adjustments, it is possible to disable the adjustments to prevent further reranging. Refer to “Local Span and Zero Control (Local Keys)” below for

more information.

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