Measuring a parameter can be easy and done without any specific equipment, like measuring small distances or counting up to a certain number. However there are measurements that can be taken only with the aid of special gadgets. These gadgets are called meters, and they allow measuring and quantifying complicated processes, monitoring parameters and comparing them to respective requirements. Such devices are used in commercial and industrial spheres, as well as in everyday life of a human. A wide range of meters was introduced, and they are distinguished by the parameter they measure. There are simple measuring instruments like rulers, thermometers, clocks, scales and gauges, there are somewhat complicated gadgets that measure moisture, pressure, wind strength and any meters measuring electric current parameters, and there are complicated and sophisticated equipment used in science, medicine and high-end technological manufacturing.