Product Overview

2 D-9502 Product Bulletin
through the positioner spring
and lever arm to impose a
balancing force against the
control pressure. When all
forces are in balance, the
positioner will not allow supply
air to pass through to the
actuator. The actuator will
establish a position proportional
to the value of the pressure from
the controller. Any change in
shaft position will inbalance the
relay, causing air pressure in the
actuator to increase or be
exhausted to reestablish a
balance at the desired shaft
position.
Application and Drawing
Identification
Operating Range
The operating range is
determined by the span and
starting point adjustments of the
positioner. The lower value of
the range is the control signal
pressure at which the actuator
begins to stroke. The upper
value is the control signal
pressure at which the actuator
reaches its maximum stroke.
The difference between the
upper and lower values of the
control signal pressure is the
operating span.
Operation Span
The operating span of the
D-9502 Positioner is adjustable
from 3 to 13 PSI (21 to 91 kPA)
and is determined by the
location of the spring in the
positioner spring arm (see
Fig. 3). When attached to the
hole closest to the positioner
cover, the spring allows a span
of 3 PSI. When attached to the
hole furthest from the cover, the
spring allows a span of 13 PSI.