Flying probes are test probes used for testing both bare circuit boards and boards loaded with components. Flying probes were introduced in the late 1980’s and can be found in many manufacturing and assembly operations, most often in manufacturing of electronic printed circuit boards. A flying probe tester uses one or more test probes to make contact with the circuit board under test; the probes are moved from place to place on the circuit board to carry out tests of multiple conductors or components. Flying probe testers are a more flexible alternative to bed of nails testers, which use multiple contacts to simultaneously contact the board and which rely on electrical switching to carry out measurements.
One limitation in flying probe test methods is the speed at which measurements can be taken; the probes must be moved to each new test site on the board, and then a measurement must be completed. Bed-of-nails testers touch each test point simultaneously and electronic switching of instruments between test pins is more rapid than movement of probes. Manufacturing of a bed-of-nails testers however is more costly.