Calibration; Process Zero And Span Adjustment; Remote Set Point Zero And Span - Emerson Fisher 4195KA Instruction Manual

Instruction Manual
D200160X012
If they are used, slowly open the upstream and downstream manual control valves in the pipeline and close the
manual bypass valve.
Calibration of 4195KS Controllers
Note
Some of the following procedures require that the proportional band knob be adjusted to between DIRECT and REVERSE. If this is
done, it will be necessary to set the proportional band knob to 400 (direct or reverse action) before replacing the proportional
band indicator cover.
If the prestartup checks revealed faulty adjustment of the process indicator, perform the calibration procedures. These
procedures are valid for either shop or field calibration, provided that open process loop conditions exist.
Note
If the controller has the auto/manual option, be sure the controller is in the automatic mode prior to performing the calibration
procedures.

Process Zero and Span Adjustment

Note
Any adjustment of the pointer span adjustment screw will require readjustment of the pointer zero adjustment screw.
1. Refer to figure 5‐1 for location of adjustments.
2. Remove the two screws (key 6) and lift off the proportional band indicator cover (key 36).
3. Set the proportional band between DIRECT and REVERSE.
4. Adjust the process pressure to the low limit of the input range.
5. Adjust the process pointer to the lowest limit of the input scale by loosening the zero adjustment locking screw and
turning the zero adjustment screw.
6. Adjust the process pressure to the upper limit of the input span. Note whether the pointer indication is above or
below the upper limit of the process scale.
7. Adjust the span screw as follows: Clockwise to increase span for a low indication; counterclockwise to decrease span
for a high indication. Adjust the span screw to correct one‐half the error.
8. Repeat steps 4 through 7 until the error is eliminated.
9. Install the proportional band indicator cover (key 36), and tighten the two4 screws (key 6).
Remote Set Point Zero and Span Adjustment (Option M)
Note
Any adjustment of the pointer span adjustment screw will require readjustment of the pointer zero adjustment screw.
4195K Controllers
July 2018
45