Instruction Manual
D200158X012
4194S Controllers
July 2018
50
3. Make fine zero adjustments by loosening the zero adjustment locking screw and turning the zero adjustment screw
(key 108). Tighten the locking screw. Refer to figure 5-3 for location of the screws.
4. Apply 100 percent of the remote set pressure input span.
5. To increase the span, proceed as follows:
a. Turn the span adjustment screw clockwise. (Adjust span to correct one‐half the error).
b. To increase the span further than the adjustment screw allows, move both ends of link A to the right. Refer to
figure 5-3 for link location.
c. Make fine adjustments with the span adjustment screw.
6. To decrease the span, proceed as follows:
a. Turn the span adjustment screw counterclockwise. (Adjust span to correct one‐half the error).
b. To decrease the span further than the adjustment screw allows, move both ends of link A to the right. Refer to
figure 5-3 for link location.
c. Make fine adjustments with the span adjustment screw.
7. Repeat the adjustments until the zero and span indications are within
±
1 percent of input span.
8. Check the pointer position at 50 percent of full pressure input span. If the error is greater than
±
1 percent of input
span, perform the Linearity Adjustment procedures.
Linearity Adjustment
Adjust the linearity by rotating the linearity adjustment screw in the curved slot on the lever arm of pivot B (key 115).
Adjusting the linearity affects the zero and span adjustment.
1. Adjust the remote set point pressure to 50 percent of the input span. The set point indicator should indicate the 50
percent mark on the scale.
2. If the pointer indicates high, loosen the linearity screw, and rotate it counterclockwise in the slot. If the pointer
indicates low, rotate the linearity screw clockwise in the slot.
3. Check the zero and span as described in the Zero and Span Adjustment procedures. Make any necessary
adjustments.
4. Repeat steps 1 through 3 until zero, span, and linearity indications are within
±
1 percent of input span.
Auto/Manual (Option E)
WARNING
Refer to the Maintenance WARNING on page 21.
Note
Each of the following procedures requires that the controller be removed from the case. Perform steps 1 through 3 of the
replacing case and cover procedure.