Views:106 Author:Site Editor Publish Time: 2019-07-17 Origin:Site
The most primitive scale in the world was invented by the ancient Egyptians. More than 7,000 years ago, ancient Egyptians used a hanging double-plate scale to weigh wheat. The scale has two weighing plates, which are suspended at both ends of the beam.
In China, the scale appeared very early. In the middle and late Spring and Autumn Period, the State of Chu had made small weighing instruments. It is Muheng Copper Ring Right, which is used to weigh the gold currency. The complete set of environmental rights is ten. Generally, it increases by multiple, namely one baht, two baht, three baht, six baht, twelve baht, one liang, two liang, four liang, eight liang, one kilogram. The Museum of Chinese History has a copper weighing pole from the Warring States Period. This weighing instrument is different from either the balance or the later weighing rod. But it is similar to the unequal arm balance. After gradual evolution, the weight arm of the weighing rod is shortened and the force arm is lengthened. It has also become a modern still-in-use scale.
Before the birth of Jesus, the pole scale was introduced into the West by the Ministry of Nomadism and was named the Rome scale. This scale is recorded in many Latin writers'works. The two arms of the Roman scale are different. The weighing arm at the end of the scale is short and the length is fixed. When weighing, you can move the weighing hammer at the other end of the scale (which changes the length of the arm at that end) until the balance reaches the horizontal state. The scale can be used to weigh objects much heavier than the scale hammer.
In 1670, Gilles Personne de Roberval (1602-1675), a famous French mathematician, physicist and mechanical designer, submitted his invented scale to the Paris Academy of Sciences in 1670. This is an equal-arm double-plate scale. The weighing tray is mounted at both ends of the weighing beam. A rigid guide rod is installed below, which can move up and down in the corresponding guide hole on the weighing seat. In this way, when the balance beam swings around the axis, the balance plate can move up and down under the action of the guide rod. But its horizontal state remains unchanged. Up to now, Roberval scale is still the most widely used commercial scale in the world.
Types of scales
There are many kinds of scales, which can be divided into needle scales, hook scales, centimeter scales, plate scales, body scale and so on. Needle scales usually have hooks to hang things. It is called a needle scale because there is a pointer on the scale as a balance indicator. If the pointer is balanced with the thing what is weighed, it will point to the middle.
At present, scales are divided into mechanical scales and electronic scales according to people's requirements and needs.
We often have table scales, pole scales, scales and body battery scale. These are based on the principle of leverage balance. In addition, there are spring scales, which are the application of elastic principle. Now electronic scales and accurate atomic scales are widely used.
With the development of society, scale plays an important role in our life. In our daily life, we can not do without the application of scales.