CALIBRATION
CALIBRATION FOR PARTICULAR APPLICATION (AV3 ONLY)
4 - 7
7. Check the speed adjustment by repeating Steps 3 and 4.
Adjust using Step 6 if necessary.
CALIBRATION FOR PARTICULAR APPLICATION (AV3 ONLY)
The following positioner adjustments may be used to tailor the
operation of the actuator to meet application requirements.
Zero Adjustment
The positioner zero adjustment can be used to set initial tension
on the range spring so that the actuator will not begin to move
from its minimum position until it receives an input signal between
four milliamps and 12 milliamps (Fig.
). This application of sup-
pression is useful when two or more actuators are to be operated
in sequence; where the actuator is equipped with a minimum stop;
or where the characteristics of the device that the actuator is mov-
ing must be matched with the characteristics of another regulated
device.
Span Adjustment
The span adjustment affords a variation of actuator motion for a
given span of input signal. For example, the span may be adjusted
to allow full actuator travel to occur with a signal change as small
as 50 percent of its full span (Fig.
). At the other extreme, the
span adjustment can be set to produce as little as 50 percent of the
travel capability of the actuator over the full input signal pressure
span.
Figure 4-4. Zero Adjustment Graph
O U T P U T
P O S IT IO N
(0 TO 100 % )
IN P U T S IG N A L
(0 TO 100 % )
T 00 77 5 A
1 0 0
5 0
0
0
5 0
1 0 0
