Samson 3767 Mounting And Operating Instructions page 46

Operation
Note:

The following applies to positioners with adapter housing for NAMUR attachment:
When the positioner and the position transmitter signal have different operating di-
rections (<< and <>), it may be impossible to adjust the zero point of the transmitter
signal due to the additional deflection caused by the bracket (28) of the adapter
housing.
In this case, readjust the black pointer (section 3.2.2 on page 16) so that the sensor
of the position transmitter reaches the control range.
Unscrew the clamp. For "actuator stem extends" (FA), shift the pointer upward to-
wards the actuator; for "actuator stem retracts" (FE), shift the pointer downward to-
wards the valve. For valves with rod-type yoke, slightly shift the positioner on the rod
in the downward (FE) or upward (FA) direction.
NOTICE
Every time you make a change as described above, the zero point and span of the po-
sitioner must be readjusted before adjusting the position transmitter.
After tuning the positioner, make sure that the vent plug of the housing cover faces
downward when the valve is installed.
46 EB 8355-2 EN