The Introduction Of Thermometer And Its History

Thermometer is a maximum thermometer, it can record this thermometer the highest temperature has measured. The thermometer should be the "back table" after use, which took the top thermometer firmly swing it down hardly, so that to make the mercury that promoted to mercury tube back in the vacuole. Other thermometers must not be swinging, which is a major difference between the thermometer and other liquid. thermometer.
The principle of work
Thermometer, also known as "medical thermometer." Work material of thermometer is mercury. Its volume of vacuole is bigger than the volume of thin tubes above. The mercury in bubble, due to temperature effects, resulting in small changes in volume. The expansion of mercury, result in significantly changing the length of mercury inside the tube. Body temperature is generally between 35 ℃ to 42 ℃, so the thermometer scale is usually 35 ℃ to 42 ℃, and the range of each degree is divided into 10 parts, so the thermometer is accurate to 1 / 10 degrees. The tube neck in the lower part of thermometer near the vacuole is a narrow curved neck, when test temperature, the mercury in vacuoles is heated then result of volume expansion , part of mercury in the neck rise to a certain position of the tube, as with the temperature to reach thermal equilibrium, the mercury column constant. When the thermometer leave the human body, the outside temperature is low, result of volume contraction of the mercury and broke on the part of the narrow curved neck, so that part of the mercury that has been promoted to the tube does not come back, mercury remains the height contact with the body.
History development
The first thermometer is invented by Galileo in the 16th century. It was not until 300 years that a easy to use, reliable thermometer to be designed.
Mercury is stored at the end of the ball. When mercury is heated, it will swell, rise along a very narrow glass tube. Therefore, a small change in temperature will lead to a substantial mercury within the glass tube rise up. After testing the body temperature, You should swing the thermometer hard, so the mercury can back to the mercury ball.
In 1714, Gabriel • Fahrenheit developed the mercury thermometer that setting the scale between the freezing point of water and human body temperature range. A Dutch doctors use it to test body temperature for fever patients, but the thermometer is still too large, most doctors can not use it very quickly.
In 1868, the German professor Wunderlich published a book "disease and the body temperature," the book records 25,000 patients at the body temperature, and the size of the thermometer he used is twice than Robert Orr Each thermometer ,it should take 20 minutes to record body temperature every time!
Later, Robert Orr in 1867 designed a fast and accurate measurement of temperature, length of the thermometer is only about 15 cm. Unfortunately, Robert Orr thermometer came late, failed to help Carl • Wunderlich.
1980, invented a talking thermometer. Membrane liquid crystal thermometer represents green when body temperature is normal, yellow represents fever, red represents high fever.
In 1988, there has been breathing pulse electronic thermometer, can be telemetry.