Weights and measures refer to the general term for objects used to measure the length, volume, and weight of objects in daily life. The development of weights and measures began around the end of primitive societies. Due to different regions and national conditions, the measurement and statistical methods are different.

In this world, there is naturally a set of standards for weights and measures. For example, the length unit has inch, 咫, ruler, zhang, xun, chang, 仞, etc.; The units of capacity include liters, buckets, hus, beans, districts, kettles, bells, overflows, and so on; Units of weight, there are come, baht, two, jin, jun, stone and so on.

The ruler is the basic unit of length, and the length of one ruler is similar to the length of one hand, which is easy to identify. It is precisely because of this that there will be a lot of deviations, because people have different heights and shortnesses, and there are differences in the length of their arms, so the standard of one foot will naturally have a little deviation.

Most of the craftsmen of this era still rely on their own experience and feel to make standards, and do not use formal measuring tools. In this way, it is not surprising that the craftsmen of the two sides are different today, and the kilns built will be discrewed, resulting in something that cannot be enclosed.

What Su Ziheng is now considering is to formulate a unified set of measurement standard units.

In the previous life, on the earth, there were the basic units of the International System of Units, such as the name of the unit of length was the meter; The unit name of mass is kilograms; The unit name of time is seconds; The unit name of the current is amperes; The unit of thermodynamic temperature is Kelvin; The unit of quantity of a substance is mole; The unit of luminous intensity is candela.

In addition to the basic units, there are auxiliary units; An export unit with a specialized name. In addition, there are countries that have selected non-SI units in accordance with their own national standards, and so on.

For Su Ziheng at the moment, many of the above units are not yet used, and it is of little significance to formulate them, and the most urgent need for him to unify is the unit of weights and measures.

After entering the base space, he flipped through many encyclopedias, found a lot of information, and combined with the many tools he had purchased himself, he decided to take two sets of standard units that were interchangeable.

Among them, the standard units used in the design and production of craftsmen are still based on the International System of Units standard on the earth in the previous life, and the decimal carry system is adopted.

The standard unit of length is meters, and the specific conversion rules are 1 meter = 10 decimeters = 100 centimeters = 1000 millimeters. In order to facilitate the conversion with the existing standards, the conversion standard rules are set 1 mile = 15 inches = 500 meters, 1 citation = 10 zhang, 1 zhang = 10 feet, and 1 foot = 10 inches = 1/3 meters.

The standard unit of area is square meters, and the specific conversion rules are 1 square meter = 10,000 square centimeters = 1,000,000 square millimeters, 1 hectare = 10,000 square meters = 15 acres, 1 square kilometer = 100 hectares, converted into acres, 1 mu = 666.67 square meters = 10 points, 1 hectare = 100 acres.

The standard unit of volume and volume is cubic meters, and the specific conversion rules are 1 cubic meter = 1000 liters = 1000 cubic centimeters, 1 stone = 10 buckets = 100 liters, 1 liter = 10 hops = 100 scoops = 1000 pinch.

The unit of quality standard is kilograms, and the specific conversion rules are 1 kilogram = 1 kilogram = 2 catties = 1000 grams, 1 ton = 1000 kilograms, 1 quintal = 100 kilograms = 50 kilograms, 1 kilogram = 10 taels (the current standard for use in this world is 16 taels) = 500 grams, 1 tael = 10 coins = 100 cents = 1000 cents.

The above are the most commonly used standard unit conversion rules for weights and measures, and larger units, or smaller units, than this one, are of little significance for current use.

After the conversion rules are formulated, it is also necessary to come up with the reference of the standard unit, otherwise it will not be possible to implement the conversion standard only if there is no reference material.

When he was teaching on the earth in his previous life, he bought many teaching tools, such as vernier calipers, scale rulers, tape measures, spiral micrometers, etc.; Electronic scales, rod scales, pound scales, case scales, table scales, physical balances, pallet balances, kilogram scales; Graduated cylinders, measuring cups, etc.

……

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It took Su Ziheng a whole morning to formulate the standards of weights and measures, and each prepared a reference.

In order to prevent the reference tool from being used too many times and being damaged, he also specially asked Pandora to scan a copy of the entire set of tools, save the data in the base brain, and when necessary, use a 3D printer to print out a copy of the tool at any time.

After lunch, Su Ziheng asked Shi Meng to invite all the craftsmen in the workshop to Bailu Academy. Taking advantage of the rest time of many students, Su Ziheng gave lectures to all craftsmen in the school.

Bailu Academy is a very small academy, and the school is naturally not large, and it can usually accommodate only thirty people. This will suddenly squeeze into nearly a hundred people, and naturally they can't all have a place to sit, so everyone simply removed their seats and all stood to listen to Su Ziheng's lecture.

Su Ziheng stood on the podium, and the whiteboard hanging on the wall behind him was filled with black charcoal with the standard unit conversion rules of various weights and measures, as well as a set of tool references placed on the podium.

Speaking of the whiteboard, Su Ziheng originally wanted to invent the blackboard first, after all, when he was a teacher in his previous life, he was used to seeing the blackboard. However, chalk was not invented for a while, and it was not convenient to dye the wooden board black, which was not as convenient as white, so he had to use the whiteboard first.

It's just that this charcoal strip is really not as convenient to use as chalk, and it is very easy to dye your fingers black. He had already planned to take advantage of Zhong Qinghan to transport a lot of gypsum this time, and take the opportunity to invent chalk.

Even he has asked Pandora to make a metal model of chalk with a 3D printer, and when the time comes, as long as he follows the encyclopedia's method of making chalk, put the gypsum into an iron pot and cook it, and then mix the plaster with limestone powder at 6:4, and then mix it with the same amount of water into the mold, and it can be dried in about 6 minutes.

With chalk and a chalkboard, it's much easier to wipe and rewrite when you're done. At least it is easier to wipe than black charcoal, so that after writing the whiteboard black, it still needs to be washed with water to wash it clean.

……

Zhong Xinde looked curiously at the standard unit conversion rules written on the whiteboard, as the leader of Zhongfu craftsmen, Zhong Xinde was naturally literate, and he knew most of the words written by Su Ziheng, but he couldn't understand the Arabic numerals, as well as the "=" sign.

Mao Boyi and other craftsmen in Sufu are just the opposite, they have already known all the Arabic 0-9 numbers, and even simple addition and subtraction arithmetic within ten have also learned, but most of the other characters have not yet been learned.

Su Ziheng looked at the people standing in the school, saw that their faces were full of doubts, raised the whip with his right hand, pointed to the text on the top of the whiteboard, and said: "Today, I want to tell you about the standard units of weights and measures, as well as their conversion algorithms......"

The moment Zhong Xinde started to speak from Su Ziheng, a hint of strangeness flashed in his eyes. He didn't expect that Su Ziheng, a little talent, would make such a sensational event and want to unify weights and measures.

For a craftsman skilled in manufacturing, Chung is well aware of the benefits of uniform weights and measures. But limited by his own ability, let alone a small craftsman, even if he is the current Xia Emperor, he can't do anything to unify weights and measures.

Today's weights and measures of the Great Xia Dynasty were handed down from the Jixia School Palace thousands of years ago. It also has its own set of conversion rules, but it can only be roughly equal, but not exactly equal.

Because it doesn't have a standard reference.

For example, the length of today's circulation, 1 zhang = 10 feet, everyone knows, but how long a zhang is, there is no absolute standard, almost in the heart of every craftsman, there is a scale of their own.

And this scale, when it is one zhang, it may not be obvious to the naked eye how big the error is, but once it is placed in one mile, this error will be as large as several zhang.

Today, Su Ziheng not only unified the conversion rules of weights and measures, but he even came up with measurement tools for specific standard units. As long as the results were measured with his tools, there would be almost no error.

This is what shocked Zhong Xinde the most!