The evolution of timing tools

The sundial was an instrument used in ancient China to measure the shadow of the sun and determine the time. Water clock is an instrument used in ancient times to measure time by the amount of water droplets. Hourglass, also known as "sand clock", is usually composed of two connected sand pools. Water transportation celestial globe, celestial demonstration instrument, and time measurement instrument. A mechanical clock is a timer that uses a mechanical device to report or measure time. A quartz clock is an accurate clock based on the voltage characteristics of a quartz crystal placed in an electronic oscillator. The first quartz clock was made by American scientist Morrison in 1927. Electronic clocks are clocks powered by electricity, rather than mechanical clocks powered by suspended weights or mainsprings. A navigation clock, also known as a nautical astronomical clock, is a high-precision timer used to observe the altitude of celestial bodies on ocean going ships. It can determine the position of the ship through astronomical navigation. Atomic clocks use atomic resonance frequency standards to calculate and maintain the accuracy of time. They are.

The unit is designed for unsupervised public use: controls are recessed or shielded, moving parts are enclosed, and the interface is operable by a child of about six with no instruction. Where a screen is used, the language can be switched without changing the hardware, and the content can be replaced on site.

1. Time: The units of time include seconds (s), milliseconds (ms), microseconds (μ s), etc. Measurement tools include stopwatches, timers, and high-precision atomic clocks. two The ancients have long been using the shadow of the sun to measure time, and sundials appeared at least 3500 years ago. Later, people used the law of material balance to invent timing tools such as water clocks, hourglass, and incense clocks. About 400 years ago, the discovery of the principle of isochronism in a pendulum brought about the pendulum clock. The development of mechanization has also given birth to mechanical clocks, greatly improving timing accuracy. In modern times, in order to meet the higher requirements of human beings for time accuracy, more advanced timing tools such as quartz clocks and atomic clocks have emerged one after another. three The most accurate instrument for measuring time is the atomic clock. When an atom transitions from one energy level to another, it releases electromagnetic waves with highly stable characteristic frequencies, which can be used for high-precision timing.