Emerson Fisher KC Series - Bourdon Tube Controller Calibration: Zero and Span Adjustment

4195KA, KB, KC, and KS Controllers
Instruction Manual
Form 5207
April 2007
6-24
6. Adjust the lower travel stop adjustment (shown in
figure 6-18) until it touches the Bourdon tube.
7. Tighten the lower travel stop adjustment lock nut.
8. Increase the process pressure to the operating
range lower limit.
9. The Bourdon tube should not touch the lower
travel stop. If it does, repeat steps 5 through 8.
10. Apply process pressure to the controller equal
to 105 percent of the process scale span.
11. Slide the upper travel stop (key 73) until it
touches the Bourdon tube.
12. Tighten the machine screws (key 75).
13. Decrease the process pressure to 100 percent
of the process scale span.
14. The Bourdon tube should not touch the upper
travel stop. If it does, repeat steps 10 through 13.
15. Adjust the proportional band to 400 percent in
the desired action and install the proportional band
indicator cover (key 36). Tighten the two screws
(key 6).
Bourdon Tube Controller Calibration:
Zero and Span Adjustment
WARNING
Refer to the Maintenance WARNING
on page 6-1.
Note
For routine zero and span calibration,
refer to the appropriate procedures in
Section 3, 4, or 5. Use the following
maintenance zero and span
adjustment procedure only if difficulty
is encountered with the routine
procedure or if nonlinearity occurs.
Refer to figure 6-19 for location of adjustments and
figure 7-1 for key number locations.
LOWER TRAVEL STOP
ADJUSTMENT LOCK NUT
LOWER TRAVEL STOP
(KEY 74)
LOWER TRAVEL
STOP ADJUSTMENT
UPPER
TRAVEL
STOP
(KEY 73)
MOUNTING
SCREW
(KEY 76)
MOUNTING
SCREW
(KEY 76)
MOUNTING
SCREWS
(KEY 75)
LOOSEN
THESE
SCREWS TO
ADJUST
UPPER
TRAVEL
STOP
56A9752-U SHT 4
A6945 / IL
Figure 6-18. Bourdon Tube Controller Travel Stop Adjustment
Provide a means of applying process pressure to the
Bourdon tube and a regulated supply pressure
adjusted to the normal operating pressure (see table
1-6). For 4195KA and KS Series controllers, connect
the controller output to an accurate gauge. For
4195KB and KC Series controllers, a gauge is not
necessary and the controller output connection may
be plugged.
Note
Any adjustment of the process pointer
span adjustment screw requires
readjustment of the process pointer
zero adjustment screw. When
checking the zero and span
adjustments, ensure that the Bourdon
tube does not contact the optional
travel stops if used (key 73 and 74).
1. Remove the two screws (key 6), and lift off the
proportional band indicator cover (key 36).
2. Set the proportional band adjustment between
DIRECT and REVERSE.
3. Set the reset valve (4195KB and KC Series only)
to 0.01 minutes per repeat.
4. Set the rate (4195KC Series only) to OFF.