Fairchild pneumatic relays perform mathematical functions on one or more input signals that result in a single regulated pneumatic output including: average & sum. Fairchild pneumatic relays meet all the requirements of a precision device including: accuracy, sensitivity & fast response. Fairchild's extensive line of pneumatic relays serves a multitude of control applications with: positive biasing, positive and negative biasing, infinitely adjustable ratio, reversing, averaging and computing, high and low pressure selectors, and high and low pressure limiting relays.