For calibration of the EM100/101 mag and other low-flow meters, SeaMetrics developed an automated piston prover. Driven by an actuator similar to those used on CNC machine tools, the prover provides precise control of both rate and volume, and can be programmed to perform repetitious flow programs automatically.

Touchscreen menus allow the prover to be used for calibration in the day, and then to be switched to research after the last production shift. Complex flow programs with many closely-spaced flow points often run and record data all night.