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INTRODUCTION

D - 1

APPENDIX D - TYPE AV1 PNEUMATIC POSITION TRANSMITTER

INTRODUCTION

This appendix covers the optional pneumatic position transmitter

kit that is available for Type AV1 positioners. This option is only

available for Type AV1__0___ positioners. The topics covered

are:

• Description.

• Installation.

• Calibration.

DESCRIPTION

The Type AV1 positioner may be used as a position transmitter by

generating a pneumatic signal that is a function of an input posi-

tion. The same combinations of signal ranges and stroke spans

are offered as in the positioner application. Those signal ranges

and strokes are: 20.7 to 103.4-kilopascals (3.0 to 15.0-pounds

per square inch gage), or 20.7 to 186.2-kilopascals (3.0 to

27.0-pounds per square inch gage) output for strokes from 25.4

to 101.6 millimeters (0.5 to 4.0 inches).

The output signal may be made a square root, linear or square

function of the input position through the use of the A, B or C por-

tion of the cam, respectively. Other characteristics may be created

by shaping the cam (Appendix C).

The Type AV1 positioner functions as a position transmitter by

interconnecting the I input signal with the 02 output port and tap-

ping into this interconnection for the output signal. A plug is placed

in the 01 port. The pneumatic position transmitter kit provides the

necessary hardware (Fig. D-1). Table D-1 lists the individual part

numbers and quantities of the items identified in Figure D-1.

A change in input (cam shaft position) causes a deflection of the

range spring via the cam linkage. The resulting force imbalance

between the signal diaphragm assembly and the range spring

causes a change in the 02 output that is fed back to the signal dia-

phragm assembly.

The signal diaphragm assembly now acts as a feedback element

by opposing the input force from the range spring. When the force

from the 02 pressure in the signal diaphragm assembly equals the

new range spring force, the output stabilizes and represents the

desired function of the input position.

ABB AV1 User Manual

Other manuals for ABB AV1