Instruction Manual
Instruction Manual
D200157X012
4194HS Controllers
October 2011
45
b. To increase the span further than the adjustment will allow, move both ends of link A to the right. Refer to figure
6 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 of the error).
b. To decrease the span further than the adjustment will allow, move both ends of link A to the right. Refer to
figure 6 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 procedure.
Remote Set Point Linearity Adjustment
Adjust the linearity by rotating the linearity adjustment screw in the curved slot on the lever arm of the short pivot B
(key 115). Adjusting the linearity affects the zero‐and‐span.
1. Adjust the set point pressure to 50 percent of input span. The set point pointer 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
adjustment.
4. Repeat steps 1 through 3 until zero, span, and linearity indications are within "1 percent of input span.
Auto/Manual Station (suffix letter E)
Note
Each of the following procedures requires that the controller be removed from the case. Refer to steps 1 through 7 found in the
procedures for replacing the differential pressure unit. Then, perform steps 1 through 4 of the procedure for replacing the
controller case and cover.
Replacing the Auto/Manual Station
Note
This procedure also permits replacement of the switch manifold O‐rings (key 312), the auto/manual tubing assembly (key 138),
and the frame gaskets (keys 4 and 5).