Multitester devices have long been used by technicians to make their job simpler. They help maintain the expensive industrial equipments, as they can make accurate electronic measurements for ohms, amperes and volts.
They are available in the digital and analog variations. However, the digital multi meter is more commonly used, as its data can be easily stored and monitored with the help of computer.
These days, you can choose between these devices that are handheld and portable or the wired, bigger ones that are packed with features. However, electronic measuring devices were not always easy-to-use and compact. The first equipments that was used to measure volts, ohms, etc. dates back to the 1800s.
In 1820, the galvanometer was the first device that was used to measure voltage and resistance. It applied the concept of the Wheatstone bridge and basic resistance of electricity. However, it had too many parts, and hence, could not be used on the field; plus, it was very slow. Soon the Weston meter replaced it. Its specialty was that, it used a fine metal spring and built-in field magnets to give measurement proportions. Sometime later, this technology was used in combination with the former one, making the measurements faster and simpler. With a series of shunt resistors added, it could calculate multiple ranges of currents with one movement.
However, automotive multimeterwas not invented until the 1900s. Donald Macadie, the British Post Office engineer, invented an instrument that could easily measure amperes, ohms, and volts all together. It was made from voltage and precision resistors, along with moving coil meters. These were known as the avometers, and were widely used in all facilities.
The vacuum tube voltmeters, also known as the valve voltmeters, were next in line of invention. Industries everywhere accepted these, as they were to be used with circuits that had high impendence. However, it specifically worked with 1 megohm circuit impendence, and hence, sometimes had problems with the lower ones. With minor changes in the voltmeter, the field effect transistor was introduced, which was followed by the analog transistor. They came enabled with varied features like capacitance, frequency, duty cycles etc. and became a must-have tool for every technician.
Lately, you will find multimeters that are enhanced with so many more functions and features. Some, like the HVAC multimeter, even come with specialized applications like the thermocouple probe, computer connectivity, inductance, etc. Hence, your everyday industrial device for measuring electrical current has come a long way from a galvanometer to the digital handheld multimeter.