4-13
EN
Rerange Procedure
To rerange the transmitter using the span and zero buttons, perform the following
procedure.
1. Loosen the screw holding the nameplate on top of the transmitter housing and
rotate the nameplate to expose the zero and span buttons (see Figure 4-11).
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.
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.
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 4-10 on
Page 4-12 for the proper placement of the transmitter security jumper.
FIGURE 4-11. Local Zero and Span Adjustments.
Disabling the Zero and Span Adjustments
After you rerange the transmitter using the span and zero adjustments, you may
wish to disable the adjustments to prevent further reranging. To disable the span
and zero adjustments, either activate the transmitter security jumper (see
“Transmitter Security” on Page 4-12) or use the sofware to disable the zero and span
adjustment buttons (HART fast key sequence 1,4,4,1,7).
NOTE
The transmitter security jumper prevents any changes to the transmitter
configuration data. The software lockout sequence only disables the local span and
zero adjustment buttons.
Span and Zero Adjustment Buttons
4690.bk : 4690.s4 Page 13 Tuesday, May 26, 1998 5:28 PM
