Adjustable
Ratio Relays
Model #'s: 1803 and 30240
The adjustable ratio relays develop a pneumatic output signal proportional to a pneumatic input signal. The output-to-input ratio is adjustable over a range from 3:1 to 1:3, and is determined by positioning a movable fulcrum on a beam. Fulcrum position is set by turning a ratio adjustment dial on the relay. Both models of the ratio relay function in the same manner and differ only in the mounting arrangement, ratio indication, and ratio adjustment knob. The model 1903 relay has a greater adjustment sensitivity range than the model 30240 because of a higher fulcrum runner gear ratio.
