Multimeters are electronic measuring instruments that combine various measurement functions in one unit. Multimeters can be hand-held devices useful for finding and correction of basic defect and field service work or bench instruments which can measure to a very high degree of accuracy. They can be used to troubleshoot electrical problems in a spacious array of industrial and household devices such as electronic equipment, motor controls, domestic appliances, power supplies, and wiring systems. Analog multimeters are usually based on a microammeter whose pointer moves over a scale calibration for all the different measurements that can be made. However, most electricians use digital multimeters (DMM).
Digits refer to the resolution of the DMM, not the accuracy. It is common to see meter specifications with 3-½, 3-¾, 4-½, etc. digit display. The half means the most significant digit can go up to 1. It originated because of 7-segment LCD/LED displays. All 7 segments are needed to display every digit. When for the most significant digit on the far left only 1 is to be displayed, only the two rightmost segments of the 7 are needed, hence the term ½ digit originated (i.e. a fraction of the 7 segments are used, very loosely approximated as a half). That was when most DMMs had a maximum reading of 1999. Recently more accurate DMMs became available, having readings up to 2999, or 3999, even 4999, so it became more complicated. Manufacturers started using the ¾ approximation.
Electricity has made life a lot simpler for the people living in this world. Except for very few tribes who live in the wilderness, everyone else has some form of electrical connection which is harvested through sources which are both renewable and non-renewable. Electricity makes so many things possible like keeping us warm during winter and cool during summer. Though there are other natural substitutes for these which are available naturally, they can be hard to setup and operate and also leaves a lot of mess. Everybody is using electricity as one of their bare necessities in life which includes both homes and huge offices. Without power, the world will be a harsh place to live for most as we are all used to the luxury which electricity brings along with it.
We know that electrical equipment makes our life easier but the equipment are very complex and it has taken years of evolution for these to come to this level. Today, electrical equipment manufacturer can contain thousands of parts and is connected using a complex circuit. The amount of power being dissipated to this equipment must be measured exactly and too much electricity or fluctuation in power can harm this equipment. This is why there are instruments which are used for measuring electricity. Electricity is also not a toy to play with. It has tremendous power which can even kill a human being and hence it needs to be operated with much care. A clamp meter is an instrument which is used to measure current. There are also other instruments which are used to measure electric current but the digital clamp meter has the advantage of measuring the high voltage of power without getting electrocuted.