Multimeters began with dead frog legs
When I was a high school freshman, multimeters were used to teach students the fundamentals of electricity in our Principles of Engineering class.
I was curious about the backstory behind multimeters since they are so common in electrical work.
Multimeters measure voltage, current, resistance and continuity of a circuit. Although, some can also measure capacitance, temperature, inductance, frequency and perform diode testing. For most beginners and enthusiasts, you'll only need the first four features which are typically found in cheaper multimeters. These measurements are so common to take today, it's difficult to imagine life 200 years ago when people were just discovering how to measure anything related to electricity.
An Italian electricity researcher, Luigi Galvani, discovered in 1791 that an electric current could make the leg of a dead frog twitch. This proved that small voltage could be detected by observing the contraction of frog leg muscles, which lead to the invention of the frog galvanoscope. This device consisted of a severed, skinned frog leg in a glass tube with two electrical connections made at the nerve. As barbaric as it sounds, the frog galvanoscope was a popular instrument to use even after other instruments were invented because it was capable of detecting extremely small voltages.
In 1820, Hans Orsted observed that a compass's needle deflects when placed near a wire with an electric current. Johann Schweigger built upon this idea by connecting a power supply to insulated wire wrapped around a compass to measure the strength of an electric current. It was named after Luigi Galvani, called the galvanometer. Throughout the 1800s, many other instruments were developed by taking inspiration from this design, including the voltmeter, ammeter and ohmmeter (measuring the strength of a current, rate of a current and resistance).
100 years later, Donald Macadie was frustrated with carrying so many tools to work on telecom lines. He sought to combine a voltmeter, ammeter and ohmmeter into one instrument. Donald named it the AVOmeter but this is referred to as the first multimeter. Many iterations of this design were explored until Fluke developed the first handheld digital multimeter in the 1970s.
Today, Fluke is one of the top names in multimeters and preferred by many professional electricians and enthusiasts. Over the years, more compact, user friendly, lightweight and accurate multimeters which offer more features have been developed. They've come a long way from frog legs. The next generation of design challenges lies in creating more user-friendly interfaces, integrating new technologies and making these essential tools even more accessible and versatile.
