A prover mounted upon a supporting lower framework includes a piston supporting rod extending longitudinally through a cylinder. Motive means supported on a frame mounted on the prover draws the rod toward the fluid receiving end of the cylinder. An upper framework is attached to the lower framework through a plurality of stanchions. Various I-beams formed as part of the upper framework enhance rigidity to the combination of lower framework and upper framework. The combination of lower framework and upper framework provides support for the prover in a horizontal or a vertical orientation without affecting the operation, repair or maintenance of the prover.