Digital multimeter having sealed input jack detection arrangement

摘要

A multimeter for testing a plurality of electrical parameters comprises a case having a plurality of test lead jacks. Each of the test lead jacks includes a unitary conductive socket. Preferably, the sockets are made of metal such as brass. A circuit board located in the case has jack conductors in electrical communication with each of the sockets. A jack detection arrangement is adapted to automatically determine whether a plug is inserted into a respective one of the sockets based on a change in electrical characteristics. For example, the jack detection arrangement may include a photonic emitter and a photonic detector situated such that a beam path therebetween is interrupted by insertion of a plug. The case may further have a rotary selector knob for selecting a multimeter function.