Barber Colman 2:1 Ratio Amplifying Relay

The 2378-501 Amplifying Relay is a proportioning device designed for use in pneumatic control systems where the application requires the amplification of a proportional signal from a controlling device. The 2378-501 branch line pressure output increases as a 2:1 ratio to the input signal pressure (up to main air pressure) and amplifies the volume of air available to the final control device, thereby minimizing system lag. The unit is factory adjusted for a 10 psig branch pressure at a signal pressure of 5 psig. A bias adjustment is provided which permits the effect of the input signal pressure to be decreased up to 9 psig from the actual input pressure