Brief introduction of balance
Balance is a commonly used instrument in laboratory. Balance is a weighing instrument, and it is also an instrument for measuring the mass of objects. It is made according to the lever principle. There are two small plates at both ends of the lever, one for putting heavy objects and the other for weighing objects. The center of the lever is equipped with a pointer. When the two ends are balanced, the masses (weights) of the two ends are equal. These truths are commonplace for people who have studied physics.
The invention of the balance was very early. In the Nile Delta of Egypt, there is an aquatic plant, which is very similar to the reed growing in our waters. Its stems are peeled off layer by layer and torn into thin slices for writing. This thing is called papyrus. Paper in many European countries evolved from Latin papyrus. Books written with papyrus are papyrus, which became an important historical document in ancient Egypt.
Much of what we know about ancient Egypt today, especially the historical development of science and technology, comes from the records in papyrus. Of course, the cursive characters on paper are not modern characters, but hieroglyphics, which many experts have seen. According to the paper cursive script, as early as 1500 BC, Egyptians had already used scales, and some people said that this time was even earlier, about 5000 BC. Although the ancient Egyptian balance was very rough, it already had the outline of modern balance and became the embryonic form of modern balance.
Use of balance
1. balance scales are generally used in scientific research institutions, school laboratories, pharmacies and other places to weigh some small measuring items.
2. Verification balance is a balance specially used by measurement department, commodity inspection department or other relevant departments or factories to check or calibrate weights.
3. High-precision balance for chemical analysis and accurate measurement of substances. In most cases, the minimum dividing value of this balance is less than the maximum weighed 10-5. Analytical balance can be divided into constant balance (weighing and minimum dividing values are 100 ~ 200g and 0.0 1 ~ 1mg respectively) and semi-micro balance (30 ~ 100~200g and1~/kloc-0). G), microbalance (3 ~ 30g and 0. 1~ 1? G) and ultramicrobalance (3 ~ 5g and 0. 1? G or less).
4. Precision balance is widely used in the accurate measurement of various substances, and its minimum dividing value is usually 10-5 ~ 10-4 of the maximum weighing.
5. Ordinary balance is used as a general measure of matter. 10-4 with the minimum division value equal to or greater than the maximum weighing value.
Price of balance scale
The well-known brands of balance scales we know are HC, COUPI, Xiangshan, Reiz and Xie Chang Electronics. These five brands are the top five in the online balance scale rankings, and the accuracy of their products can be said to be truly accurate. Their prices are different. For example, the balance scale of HC brand is slightly more expensive, the article number UTP3 13-4, the weighing range is 300g, the dividing value is 0.0 1g, and the price of Tmall flagship store is 228 yuan. The upgraded version of the 500g weighing range costs 288 yuan, and the 600g costs 298 yuan. It can be said that the larger the weighing range, the higher the price, and the lowest of other models is above 80 yuan. The prices of Xiangshan, Kubi, Zhi Zhi and Xie Chang are basically the same. The lowest price will not be lower than 20 yuan, and the highest price will be within 80 yuan. Basically, products from around 50 yuan can meet our needs. And the quality and accuracy are excellent.
Of course, there are five other brands, namely Wei Heng, Livingstone, Leluan, Diheng and Supreme, which are second only to the above five brands. Its price basically ranges from 30 yuan to 50 yuan. Among them, the product price of Diheng brand will be slightly more expensive than other brands. This is mainly related to its product range. The normal price is about forty or fifty yuan, and you can buy a suitable scale. High-precision balance scales used to weigh jewelry will be more expensive, basically around 200 yuan, or even higher, except for conventional balance scales.
Note: This price is for reference only! Of course, due to different regions, the price will be different. For more detailed information about relevant prices, please refer to the information provided by local dealers!
How to make a self-made balance scale
Production steps
1. Understand the experimental equipment: double-sided tape balance ruler, upright post, O-ring plastic wire, small dish, basis weight, pointer, copper wire, hook and small shaft.
2. Use three plastic wires to hang Fluttershy in the three small holes on the platter. (Cut the copper wire in half) Tie the hook and the three plastic wires with copper wires at equal distances. Then use double-sided tape to fix the pointer in the middle of the balance ruler and keep it perpendicular to the balance ruler.
3. Insert the column into the base, fix the balance ruler on the column with a small shaft, hang small discs on the small holes at both ends of the balance ruler, and adjust the balance with O-rings until it is balanced. Put the weights with different or the same grams into two Fluttershy, and carry out the balance experiment. Put the weights with different weights and equal weights on two trays respectively, and you can know that if things with different weights are placed on both sides on the same day, the balance will be unbalanced and which side the balance will fall to; When things on both sides are equally heavy, the balance will be balanced. Put unequal weights on the two trays of the balance to find out the imbalance. Adjust the tray at one end of the balance so that it hangs on the balance until it is balanced. Put equal weights on the two trays of the balance and find that the balance is balanced. The tray at one end of the adjustment balance is hung on the scale, and the balance is unbalanced. Through experiments, it is found that putting weights with equal weight on the balance will lead to the imbalance of the balance because of the different positions of the tray hanging on the level; The weights of different weights are placed on the balance, and the balance will be balanced because the tray is hung in different positions on the level.
Matters needing attention
1. Move the roaming code to the 0 scale ahead of time and adjust the balance nut. When adjusting the balance nut, it is best to balance the balance left and right with tweezers.
2. Put the weight on the right and the object on the left.
3. You can't hold the weight by hand, but use tweezers. You can't move the code by hand when using the sky.
4. The objects that are too cold and too hot should not be weighed on the balance. Before weighing, it should be placed in a dryer to room temperature.
5. The weight should be increased from large to small, which can save time.
6. Do not touch the balance nut again during weighing.
Editor's summary: Self-made scales have many advantages. We can design them into our favorite types, give play to our hobbies, learn relevant knowledge and exercise our hands-on ability. The hands-on production process may not be successful at first. Be more patient and I believe you will get the desired results.