The multimeter is an invaluable aid to the electronic and electrical engineer. Many years ago these professionals would have had to carry up to three test meters to test the properties of electrical circuits. A Voltmeter for measuring electrical potential in volts, an Ammeter for measuring electrical current in amperes and an Ohmmeter for measuring electrical resistance in ohms.
These were combined into a single meter called a Multimeter. Early designs featured an analogue display, based on a moving coil meter. Electrical signals would be converted by means of resistors and switching networks within the meter, these signals would then pass through coils which would rotate a magnet. Attached to the magnet would be a pointer which would deflect over a scale as the magnet rotated.
Modern multimeters are now much more compact and reliable, the analogue display has been replaced by an LCD (Liquid Crystal Display) which provides accurate readout of the properties of the circuit under test.
