Precision pressure-responsive fluid gauge

In a pressure-responsive gauge of the type having a base, a balance beam, a fulcrum pivotally supporting said beam relative to said base, pressure-responsive means interposed between said base and said beam arranged to tilt said beam, a poise slideable along said beam to counter-balance the force of said pressure-responsive means, drive means for moving said poise, said drive means including a flexible member extending parallel to said beam and a servo-motor arranged to move said flexible member, an armature attached to one end of said beam, a differential transformer excited by said armature, an electric circuit including said transformer and said servo-motor functioning to move said poise to null said transformer and a read-out driven by said servo-motor, the improvement comprising temperature responsive means to compensate for temperature variations in a vertical sense comprising a first spacer between said pressure-responsive means and said base of a different material than said pressure-responsive means, said firt spacer and said pressure-responsive means having dimensions and coefficients of expansion such that they expand to the same extent as said fulcrum, a clamp adjustably clamping said transformer vertically relative to said base, a second spacer between said beam and said armature, and a third spacer between said base and said clamp, the materials of said clamp, armature and spacers being such that the position of the midpoint of said armature relative to the null point of said transformer remains fixed despite temperture variations.