What are the ancient measuring tools?

A measuring tool is a tool for measuring certain properties. Include length, temperature, time, mass, force, current, voltage, resistance, sound, radio, refractive index and average dispersion. Some mechanical measuring tools, such as square and caliper, were first used in mechanical manufacturing.

Multimeter, also known as multimeter, multimeter, three meters, multimeter, etc. , is an indispensable measuring instrument for power electronics and other departments. Its main purpose is to measure voltage, current and resistance.

Multimeters are divided into pointer multimeter and digital multimeters according to the display mode. It is a multifunctional and multi-range measuring instrument. Multimeters can generally measure DC current, DC voltage, AC current, AC voltage, resistance, audio level, and some can also measure AC current, capacitance, inductance and some parameters of semiconductors (such as β).