Abstract: An apparatus for blending two gases together in precisely adjustable proportions. The apparatus includes a mechanically adjustable, blending subassembly adapted to receive the first gas at a predetermined pressure and a one to one force balanced pneumatic relay which is operated by the first gas and which meters the flow of the second gas to the blending subassembly at a pressure substantially equal to the pressure of the first gas being supplied to the blending subassembly.
Abstract: An apparatus for blending two gases together in precisely adjustable proportions. The apparatus includes a mechanically adjustable, blending subassembly adapted to receive the first gas at a predetermined pressure and a one to one force balanced pneumatic relay which is operated by the first gas and which meters the flow of the second gas to the blending subassembly at a pressure substantially equal to the pressure of the first gas being supplied to the blending subassembly.