Marconi Instruments Limited was a UK-based company, formerly part of GEC.
The company was making electronic test and measurement equipment and systems, such as ATE systems. It was famous for its extensive range of signal generators, from audio up to microwave frequency range. It also made some oscilloscopes, voltmeters, spectrum analyzers, counters, function generators, LCR bridges, impedance analyzers, power supplies, distortion analyzers and logic analyzers. The company operated an approved calibration and metrology laboratory for the electronics industry as well.