The measurement significance of World Survey Day

As we all know, science and technology is an important foundation for human survival and development. Without science and technology, there would be no human beings today. In fact, measurement itself is an important part of science and technology. Any science and technology is to explore, analyze, study, master and use the objective laws of things; And everything is composed of a certain amount, which is reflected by it. In order to know this quantity and get its value accurately, only through measurement. For example, Copernicus's theory of celestial motion was put forward on the basis of repeated observations and was established after Galileo made further observations with astronomical telescopes; The famous law of gravitation was revealed by Newton's keen observation, and was confirmed by Cavendish's precise experiment more than one hundred years later. Einstein's theory of relativity is also verified on the basis of accurate frequency measurement. Li Zhengdao's and Yang Zhenyu's theory of parity non-conservation under weak interaction has also been verified by Wu Jianxiong and others through special tests in the US Bureau of Standards and Technology. In short, from classical Newtonian mechanics to modern quantum mechanics, all kinds of laws and theorems are revealed, recognized and established through observation, analysis, research, reasoning and practical verification. Measurement is an important technical basis of the above process.

Three great technological revolutions in history all fully relied on metrology and promoted its development.

The first technological revolution, marked by the wide application of steam engines, led to the replacement of manual workshops by machinery-based factories, which quickly improved productivity and established capitalist production methods. At that time, classical mechanics and thermodynamics were the important theoretical basis for the development of social science and technology. During the development and application of steam engines, it is necessary to measure steam pressure, thermal expansion coefficient, fuel combustion efficiency and energy conversion. Mechanical metrology and thermal metrology are developed in this situation. In addition, the rise of machinery industry has further developed the measurement of geometric quantities.

The second technological revolution marked by the generation and application of electricity further promoted the development of society. Ohm's law, Faraday's law of electromagnetic induction and Maxwell's electromagnetic wave theory provide an important theoretical basis for the in-depth study and wide application of electromagnetic phenomena and the development of electromagnetic metrology and radio metrology. For example, the thermoelectric effect discovered by Sibeck in 182 1 year laid a theoretical foundation for the birth of thermocouple; The successful development of various thermocouples provides an important means for temperature measurement, electrical measurement and radio measurement, and promotes the development of corresponding science and technology. In order to actually measure the relative speed of the earth's movement, Michelson and others developed Michelson interferometer by using the achievements of physics, thus providing an important method for length measurement. 1892, Michelson used the pickaxe light (monochromatic red light) as the light source of the interferometer to measure the length of the reference meter of platinum-iridium alloy preserved in Paris, and obtained quite accurate results (equal to 1 553 163.5 red light wavelength). Until more than one hundred years later, it is still an important method to accurately measure the length by using various interferometers. Planck's energy state quantization hypothesis points out that when an object radiates and absorbs energy, its charged linear harmonic oscillator can exchange energy with the surrounding electromagnetic field, thus jumping from one energy level to another. What is the energy of the energy quantum? E = h nu (where h- Planck constant, nu- frequency). On the basis of Planck's hypothesis, Einstein proposed that light is not only wave-like, but also particle-like, that is, light is a particle (photon) stream moving at speed c, and its unit (photon) energy is? E=hυ, indicating that photon energy at different frequencies is different. The above theory successfully explained the photoelectric effect, which became the theoretical basis of thermal radiation measurement, and also made the measurement begin to enter the micro field from macro. With the establishment and development of quantum mechanics and nuclear physics, the measurement of ionizing radiation has gradually formed.

The development and application of nuclear energy and chemical industry led to the third technological revolution. During this period, the development of science and technology and social economy is more rapid. With the wide application of new technologies such as atomic energy, chemical industry, semiconductor, electronic computer, superconductivity, laser, remote sensing and aerospace. The measurement is becoming more and more modern, and the macroscopic physical standard of measurement is gradually changing to the quantum (natural) standard. The establishment of atomic frequency standard and the formation of a new definition of rice are of great significance. Accurate measurement of frequency and length promotes the development of modern science and technology. For example, the measurement of light speed, the detection of ultra-fine structure of atomic spectrum, and many scientific and technological fields such as navigation, aerospace, remote sensing, laser and microelectronics are all based on accurate measurement of frequency and length.

As for the so-called fourth technological revolution, which is widely discussed and concerned, it will cause great changes in science and technology, economy and society, and mankind will enter a "super-industrial society" or "information society". By then, non-renewable fossil fuel energy will be replaced by renewable solar energy, tidal power generation and other new energy sources, and traditional industries such as steel, machinery and rubber will be conquered by emerging industries such as electronic industry, aerospace engineering, marine engineering and genetic engineering, and so on. Microelectronics and computers are pioneers of this technological revolution, and integrated circuits can be said to be the core of pioneers. Without the corresponding measurement guarantee, the development of integrated circuits is unimaginable. For example, the measurement and control of the geometric parameters and physical properties of silicon single crystal, the purity of ultra-pure water and ultra-pure gas, the properties of chemical reagents and photoresist, the thickness and dislocation of thin films, the depth, concentration and uniformity of ion implantation, and the test patterns of process monitoring are all precise measurements. At present, the development of integrated circuits in China is still relatively backward, one of the reasons is that the measurement work can't keep up.

In short, the development of science and technology, especially the achievements of physics, has created an important premise for the development of metrology, and at the same time put forward higher requirements for metrology and promoted the development of metrology; The achievements of measurement have promoted the development of science and technology. As Mendeleev said, "Without measurement, there is no science". Comrade Nie Rongzhen also clearly pointed out: "To develop science and technology, measurement must go first"; "If you don't measure it, you can't move." The function and significance of measurement to industrial production are obvious. Socialized mass production itself needs a high degree of measurement guarantee. The development of production can be roughly divided into three stages, namely, empirical stage, semi-empirical stage, semi-scientific stage and scientific stage. Measurement is the technical basis of scientific production. From the screening of raw materials to fixed feeding, from process monitoring to product quality inspection, it is inseparable from measurement. For example, an ordinary truck has more than 9000 parts, which are produced by hundreds of factories. Without certain measurement guarantee, it is impossible to assemble successfully. The oil consumption of rolled steel plates in a local medium-sized steel plant used to be more than 300 kilograms per ton. Later, due to the measurement and monitoring of waste gas, air volume, combustion heat supply and temperature, the energy consumption dropped to 40 kg per ton. It turns out that the heavy oil fuel used in the metallurgical furnace of a steel plant is controlled by manual experience and is not measured at all; In order to make the fire prosperous, more materials are always put in, which leads to incomplete combustion and black smoke rolling, which not only consumes more oil, but also pollutes the environment and loses money every year. Later, a metering instrument was installed to monitor the fuel, so that the fuel quantity was kept at the optimal value, which not only saved oil, but also reduced pollution and improved steelmaking efficiency. As a result, a new situation of turning losses into profits soon appeared. A Masteel is the largest producer of Masteel products in China. In the past, energy consumption has been very high, and it is the key household of local energy consumption. In order to find out the reason, the factory conducted thermal balance tests on more than ten kinds of main equipment, and obtained a lot of data, thus calculating the basic relationship between thermal balance and equipment energy consumption, preliminarily grasping the law of energy utilization, finding out the main reasons for serious energy consumption, and installing monitoring instruments accordingly. For example, the thermal efficiency of the annealing kiln is about 8%, but after monitoring and control, it has increased to more than 65,438+02%, and the annealing time has been reduced from 60 hours to 35 hours, saving nearly 2,000 tons of coal and more than 26,000 kWh of electricity a year. As a result, in one year, the water consumption of the whole plant decreased by 2 1%, saving about 600,000 kWh, reducing the comprehensive energy consumption by about 10%, and increasing the output value by 22%.

In recent years, foreign developed countries regard high-quality raw materials, advanced technical equipment and modern measurement and testing methods as the three pillars of modern production. In fact, the preparation and screening of high-quality raw materials, advanced technology equipment and process monitoring are also inseparable from measurement and testing. For example, the products of foreign advanced production lines are of high quality, with little or no secondary and waste products. One of the important factors is to make full use of online measurement and monitoring technology. As for the so-called flexible production (manufacturing) system, it needs the technical support of modern measurement and testing means.

As for agricultural production, especially modern agricultural production, there must also be metrological guarantee. For example, scientific farming needs to master the soil pH, salinity, moisture, organic matter, nitrogen, phosphorus and potassium content and temperature through measurement. In the process of selecting seeds in salt water, soaking seeds in warm soup or medicine, accelerating germination at suitable temperature, centrifugal dehydration, etc., it is also necessary to rely on certain measurement guarantee. Ionizing radiation breeding is an important yield-increasing measure developed in recent years. Many new crop varieties have been cultivated in China by this method, among which Lumian 1 can double the cotton yield in a large area. The preservation of agricultural products and food by ionizing radiation is also an important aspect of the emerging radiation processing industry. These all need corresponding measurement guarantee, otherwise it will not only fail to achieve the expected effect, but also cause undue losses. In addition, in the field management, it is also inseparable from measurement. For example, close planting and interplanting are needed, so it is necessary to measure the light of plant photosynthesis.

Facts fully show that scientific production and technological innovation cannot be separated from measurement and testing. The significance of measurement to people's lives is quite obvious. The measurement of production process can not be ignored, and the measurement of life should be paid more attention to. It directly touches people's vital interests and is sometimes very sensitive. For example, whether the measuring instruments in daily business are accurate, whether household electric meters, gas meters and water meters are qualified, and even whether the time of public transportation is accurate will have a certain impact on people's lives.

Bread is the pillar of life. Food is a necessity of life, and no one can live without it. The quality of food is directly related to people's health. In the process of grain production, applying chemical fertilizer can increase production, and spraying pesticides can kill insects. However, most chemical fertilizers and pesticides are harmful to human body and must be controlled within a certain dose, otherwise it will lead to cumulative poisoning and serious consequences. Many countries, including China, have banned some pesticides, such as HCH. In recent years, some developed countries are actively exploring a new type of agriculture that does not use chemical fertilizers and pesticides at all, that is, the so-called "ecological agriculture", which deserves attention. If successfully promoted, it will have a far-reaching impact on human survival and development.

Food preservation is a problem that people pay more and more attention to. It has been proved by the medical profession that food and its products will produce aflatoxin when they are moldy and deteriorated, which is easy to cause cancer after being eaten by people and animals. In addition, some additives, such as pigments, flavors, preservatives, etc. It is often added in food processing, so necessary measurement and testing should be carried out to control the dosage, otherwise it will lead to adverse consequences and endanger people's health. Therefore, the production, storage and processing of grain and its products are inseparable from measurement.

Frozen preservation of non-staple foods, especially aquatic products, meat, eggs and vegetables, has been widely used. In this respect, temperature control is very important. Too low temperature will destroy the color, fragrance, taste and even nutrition of food. If the temperature is too high, it is not easy to store. This can only be guaranteed by corresponding measurement.

In recent years, all kinds of pollution in cities have become increasingly serious, which has almost become a public hazard that is difficult to eradicate. All countries in the world, especially the more developed countries, attach great importance to environmental protection. Among them, the key link is effective measurement, monitoring and control, such as air, water quality and noise. As for the importance of water and air to life, it goes without saying. Social surveys show that in some areas with good water quality and fresh air, especially in mountainous areas, people's average life expectancy is longer; On the contrary, in areas with poor water quality and serious air pollution, people's morbidity is higher and their life expectancy is generally lower. In recent years, through the measurement and testing of air, it is found that when the concentration of negative ions in the air is high, the air will be particularly fresh, which has a certain medical and health care effect on people. This is one of the reasons why sanatoriums, sanatoriums and health centers are often built in mountainous areas, forests, beaches and lakes.

In the field of medical and health care, the role of metrological testing is becoming more and more obvious. The prevention, diagnosis and treatment of diseases in modern medicine are inseparable from metrological testing. For example, measuring body temperature, blood pressure, electrocardiogram, electroencephalogram and various tests are common metrological tests. People pay attention to cancer, which is one of the diseases with the highest mortality. According to the estimation of American experts, about14 of the total population may suffer from various cancers in their lifetime. Of course, the degree of illness varies. Today, there are more than one million cancer patients in some countries. Among them, about 70% patients received radiotherapy, but only about 40% patients were cured. The radiation dose received by the tumor site is required to be accurate to 5%. Because the dose is small, it is not enough to inhibit and kill cancer cells; If the dose is large, the patient will suffer unnecessary harm. This can only be guaranteed by measurement. Measurement and domestic trade are slightly involved, which is generally felt; Let's just talk about measurement and international trade.

There are many examples that need to be measured in foreign trade. For example, in the past, our country exported apples only by observing their appearance or tasting them directly, not by measuring them. Some foreign businessmen use it to make things difficult and cut prices at will. In fact, it is very simple to measure the maturity of apples, as long as the hardness value corresponding to maturity is determined and measured with an ordinary hardness tester. For another example, in the past, due to the lack of accurate and reliable metering equipment in the port, China often used the method of loading more oil to avoid the claim, and even the shipowner's claim was overweight because of too much oil, which is a pity. At present, the annual output of crude oil in China has exceeded10.40 billion tons, and a considerable amount of crude oil is exported every year. The measurement accuracy of crude oil in general ports is about 0.5%. If the accuracy is improved, even if it is only increased by 0. 1% or less, a large amount of crude oil will be lost in one year, which can not only obtain obvious pseudo-economic benefits, but also reflect the measurement level of our country.

As for the goods imported by our country, the situation of insufficient quantity and inconsistent quality occurs from time to time. For example, not long ago, Tianjin imported silicon steel sheets worth millions of dollars from abroad. After measurement and testing, it was found that the quality was unqualified and a claim was made to foreign countries. As a result, in the face of accurate measurement data, foreign businessmen have to admit their mistakes and make compensation. China has imported a batch of chemical fertilizers, but it is found that the quantity is obviously insufficient, even less than the nominal weight on the packaging bag 10% or more.

People are increasingly aware that measurement is an important means to ensure product quality and improve the competitiveness of commodity markets. correct

In international trade, measurement is to eliminate trade, and measurement is an important means to eliminate technical barriers to trade. Measurement is particularly important to national defense, especially cutting-edge technology. The sophisticated national defense system is huge and complex, involving a wide range of scientific and technological fields and high technical difficulty. It requires many parameters, high precision, large measuring range and wide frequency band. For example, due to the increasing distance between the aircraft and the ground, higher requirements are put forward for communication, tracking, orbit measurement and positioning. As far as satellites are concerned; The military communication synchronous satellite can reach 35 800km from the ground, and the nuclear explosion detection satellite can reach 1 12 280 km from the ground. Communication by radio requires a high-power transmitter and a high-sensitivity receiver, so the main parameters such as high power, low noise, large attenuation and low voltage must be measured accordingly. This requires not only the study of testing methods and equipment, but also the establishment of corresponding measurement standards. At present, the average transmission power of ground equipment can reach tens of kilowatts, and the noise temperature of the receiver can be lower than 15K. In order to improve the control ability of aircraft, the requirements for the accuracy of tracking, positioning and speed measurement are getting higher and higher, not only for electronic parameters, but also for equipment processing and servo control components. In the continuous wave metering system, the short-term stability of the ground frequency standard should be above 10 in order to ensure the speed measurement accuracy to reach several centimeters per second. In the space system, the communication between ground equipment and the detection and control of space vehicles on the ground require high-speed transmission and processing of a large amount of data. Therefore, the transmission signal is required to have wide frequency band and high precision. International communication and broadcasting satellites generally use11GHz ~14 GHz, 20GHz-40GHz or higher, and continue to develop into millimeter wave and submillimeter wave. It is necessary to develop new components, parts and even the whole machine, which will inevitably put forward new requirements for measurement and testing.

For the national defense advanced technology system, the working environment is special, and it is often difficult to carry out effective measurement and testing on the spot. For example, aircraft will experience a series of harsh environments such as vibration, impact, high temperature, low temperature, high humidity and strong radiation during transportation, launch, operation and recovery. When the warhead enters the atmosphere, it will be subjected to ultra-high temperature above several thousand degrees; The key components to improve the sensitivity of the receiver generally work at the ultra-low temperature of liquid helium; The thrust of the main engine can reach tens of meganewtons, while the thrust of the attitude control engine is only a few centinewtons. The development of atomic bombs, hydrogen bombs and other nuclear weapons and explosive power experiments have special requirements for measurement, and a series of measurement tests such as dynamic pressure, dynamic temperature, pulse flow and nuclear radiation must be carried out.

Because the measurement test provides the required data, it ensures the reliability of all components, subsystems and the whole system; At the same time, it can also shorten the development cycle and save manpower, material resources and time. For example, an aviation jet engine company in the United States needs to carry out a series of measurement tests in the process of developing new engines. When the error of measuring instrument is 0.75σ, 200 experiments are needed and the cost is 20 million dollars. When the measurement error of the instrument is reduced to 0.5σ, only 28 experiments are needed, and the cost is only 2.8 million dollars.

199 1 In the Gulf War, accurate measurement and testing was one of the important reasons why Patriot missiles successfully intercepted Scud missiles.

Visible, in the national defense construction, measurement and testing is an extremely important technical foundation, with obvious technical support, not only can save money; Strive for time, improve combat capability, and provide reliable basis for commander's judgment and decision.

As can be seen from the above examples, metrology is an important technical basis for scientific and technological progress and economic and social development. On the other hand, with the development of the situation, the requirements for measurement are getting higher and higher, especially for accuracy and reliability, which stimulates the development of measurement itself. Nowadays, it is no exaggeration to say that any science, any department, any industry or even any activity needs measurement directly or indirectly, intentionally or unintentionally. The measurement level has become one of the important symbols to measure the degree of scientific, technological, economic and social development of a country. Measurement is an important guarantee of market economy.

Metrology science and technology plays a very important role in establishing and maintaining the socialist market economic system. This is because "quantity" is the manifestation of all objective things and their movements, reflecting the internal nature, mutual relationship and laws of movement of objective things. With the development of human society and the continuous improvement of the market economy system, various activities are becoming more and more socialized, especially in trade and scientific and technological exchanges, there should be relatively consistent measurement results for the same "quantity", which requires the unity of measurement units and the accuracy and reliability of measurement, that is, to ensure it by measurement, otherwise the social and economic order will be chaotic, production and circulation will not be carried out normally, and scientific experiments and high-tech research and development will also encounter difficulties. As Marshal Nie Rongzhen said, "With the development of science and technology today, it can be said that it is difficult to move forward." In the socialist market economy, measurement is an indispensable technical foundation. China has promulgated laws and regulations such as People's Republic of China (PRC) Metrology Law, Administrative Measures for Compulsory Verification of Working Measuring Instruments in People's Republic of China (PRC), Regulations on Measurement Supervision of Retail Commodities, Regulations on Measurement Supervision of Quantitative Packaged Commodities, and Regulations on Punishment for Illegal Measurement of Commodity Quantity, which reflect the important role of measurement in the market economy.

Metrology is an important means of scientific research.

In the development of natural science, metrology is an indispensable means for people to correctly understand natural phenomena, master natural laws and verify scientific foresight. For example, Dr. Wu Jianxiong, an American Chinese, verified the theory of parity non-conservation under weak interaction proposed by two world-renowned physicists, Dr. Li Zhengdao and Dr. Yang Zhenning, through accurate measurement in the laboratory of the National Institute of Standards and Technology. In the research of life phenomena, gravitational waves, earth science, material science, informatics and so on, accurate measurement and testing are needed. In industrial production, not only the processing and installation of general parts need measuring and testing means. In the construction of information superhighways, high-rise buildings and high-speed elevators, in the production of optical fibers, laser devices and geodesy, and in the production of large-scale integrated circuits, the uncertainty of measurement and testing of geometric parameters, refractive index distribution, bandwidth and other parameters is also increasing. In medical care, inaccurate measurement often leads to personal accidents. In tumor radiotherapy, the dose of X-ray and γ-ray is closely related to the therapeutic effect.

If the radiation dose exceeds the standard, the patient's good tissue will be burned or damaged, and if the radiation dose is insufficient, the therapeutic effect will not be achieved. If the spectrophotometer is not accurate, the analysis result of liver function will be unreliable and so on. The development and production of computer industry, ferrous and nonferrous metallurgy industry, new energy, environmental science and technology, and national defense construction all need metrology science and technology. Measurement not only involves various economic fields, but also is closely related to people's life and safety. Metrology plays an important role in aerospace, aviation, navigation, mining, earthquake, electric power, petrochemical, textile, transportation, meteorology, communication and other fields.