3-5
EN
Setting the Span
Setting the span of the transmitter involves applying pressure and adjusting the
potentiometer accordingly. To set the span of the transmitter, use the following
procedure:
1. If the transmitter does not have a readout device, attach an ammeter using
the test terminals in either compartment (see Figure 3-2 on Page 3-3).
2. Ensure that the selector switch is in the “RUN” position. Expose the
transmitter to full scale pressure.
3. Set the selector switch to “S.”
4. Using the potentiometer, adjust the transmitter output until the readout
device reads the 20mA.
5. Return the switch to “RUN.”
The selector switch should not be set to the “Z” position unless the potentiometer will be
adjusted. Failure to adjust the potentiometer while in the “Z” position will result in erroneous
transmitter output during an overpressure event, and a shift in calibration after the
overpressure event. The transmitter can be returned to normal operation by performing
either of the following procedures:
1.Remove power from the transmitter while the selector switch is in the “RUN” position,
and re-apply power. This will reset the former zero calibration.
OR
2.Calibrate the zero point of the transmitter by following the instructions in the section
entitled “Setting the Zero.”
4690.bk : 4690.s3 Page 5 Tuesday, May 26, 1998 5:28 PM
