This year's "Dog Day" starts on July 17 and ends on August 25. In the hot summer, everyone is more concerned about the daily temperature. Temperature is too closely related to our daily life. Elderly people are accustomed to paying attention to the "weather forecast" program after "News Network" every day. Young people prefer to check the dynamic information of the weather directly on the mobile phone, and the temperature that accompanies the weather changes. Often determines the dress or schedule in the next few days. I have some fever in my body or my family, so I will use a thermometer to measure it. Today we will talk about the story about the pyrometer. First, we will talk about the invention of the two color pyrometer, secondly, the establishment of the temperature scale, and finally the process of introducing the knowledge of the two color pyrometer into our country.

1. The invention of the two color pyrometer

You may be wondering, how did humans express temperature before the invention of the two color pyrometer? It's very simple, described by experience. You may remember the story of "Two Children Arguing for Days" in the Warring States "Liezitang Questions". One child defended "the nearer is hot and the far away is cool", "It is cold and cold at the beginning of the day, and it is like exploring in the middle of the day. Soup". This is a very simple empirical description. Of course, the ancients also figured out a slightly more advanced method of detecting temperature, such as the "Zhaozi" in firing ceramics. So what is "Zhaozi"? Simply put, it is the mud embryo that the kiln worker uses to distinguish the temperature of the kiln fire. According to the research of Professor Zheng Naizhang of Jingdezhen Ceramics University, Zhaozi had appeared in the Wei, Jin, Southern and Northern Dynasties, but it was mainly used to test glaze color at that time; by Song and Yuan Dynasties, the technology of Zhaozi had matured. By observing the sintering degree of Zhaozi, the products in the kiln were tested at the highest firing temperature. The length of the holding time. This kind of technology relies on the accumulated experience of the kiln workers and cannot be quantitatively and accurately detected.

The invention of the two color pyrometer is a product of the modern scientific revolution in the West, and Galileo first invented a gas two color pyrometer that uses the principle of thermal expansion and contraction of air. The West has a long history of exploring the expansion and contraction of air and its application. As early as the ancient Greek period, the famous Hero of Alexandria used this principle to design an automatic door opening mechanism that can be used in temples. Galileo's two-color gas pyrometer is very simple, it is a thin glass tube with one end open and the other end is an egg-sized glass bulb. When using, first cover the glass bulb with your hands, then let one end of the glass bulb be up, and insert the glass tube vertically into the water, which forms a simple gas two color pyrometer. When the outside air rises or falls, the water column in the glass tube will fall or rise. If a scale is marked on the glass tube, the temperature can be indicated. Although it is not clear how Galileo marked the temperature at the time, he clearly mentioned the degree in a book. However, because this two color pyrometer will be affected by the air temperature in the bubble and the outside air pressure, the error is relatively large. Inspired by Galileo, his friend Sanctorio Sanctorius (Sanctorio Sanctorius), a professor of medicine at the University of Padua in Italy, invented a serpentine gas two color pyrometer in 1612. The upper glass bulb can be put into the patient. In the mouth, check the patient's body temperature from the water column below. This is the earliest clinical thermometer in the world.