Abstract: A hydrostatic test system for subjecting a workpiece or test specimen to a predetermined test pressure until the workpiece fails by developing a leak detectable by the test system. The hydrostatic test system is a modular system readily adaptable to, and able to incorporate therein, a number of different physical devices for regulating, controlling, detecting, and registering functions and activities pertaining to leak detection. Among the devices adaptable in the hydrostatic test system for detecting a leak condition in the workpiece is a differential pressure switch and a static pressure switch, a combination differential and static pressure switch, or an accumulator associated with either a pressure transducer or a high accuracy transducer. The leak condition may be visually signaled by a lamp or indicator light or the sensing of a leak condition may be visually output to a CRT screen.