Mercury Thermometers
Mercury in glass thermometer is a thermometer made from mercury placed in a glass tube. Signs are calibrated on the tube make the temperature can be read according to the length of the mercury in the glass, varies according to temperature. To improve accuracy, there is usually a water bulb mercury at the tip of the thermometer which contains most of the mercury; expansion and narrowing of the volume of mercury and then proceed to the tube more narrow. The space between the mercury can be filled or left empty. In lieu of mercury, some families contain alcohol thermometers with the addition of red dye. This thermometer is safer and easier to
read. A special type of thermometer mercury, called the maximum thermometer, working with the valve on the neck of the tube near the bulb. When the temperature rises, the mercury is driven upwards through the valve by the force of expansion. When the temperature drops of mercury retained on valve and can not return to the bulb make the mercury remains in the tube. The reader can then read the maximum temperature during the time predetermined. To restore its function, the thermometer should be swung hard. This thermometer medical thermometer-like design. Mercury will freeze at a temperature of 38.83 ° C (37.89 ° F) and can only be used at temperatures above it. Mercury, unlike water, does not expand when frozen so it does not break the glass tube, making it difficult observed when it freezes. If the thermometer contains nitrogen, the gas may flowing down into the column and trapped there when the temperature rises. If
This happens thermometer can not be used until the return to initial conditions. To avoid this, the mercury thermometer should be inserted into the a warm place at temperatures below 37 ° C (34.6 ° F). In areas where the maximum temperature is not expected to rise above 38.83 ° C (37.89 ° F) thermometer that uses a mixture of mercury and thallium may be used. This thermometer has a freezing point of 61.1 ° C (78 ° F). Mercury thermometers commonly use the Celsius temperature scale and Fahrenhait. Anders Celsius Celsius scale formulation, presented in its publication "The Origin of the Celsius temperature scale" in 1742. Celsius used two important points on the scale: temperature when the ice melts and the temperature
evaporation of water. This is not a new idea, since Isaac Newton first worked with
something similar. Celsius temperature measurements using the melting temperature and
instead of freezing temperatures. Experiment to get a better calibration on the Celsius thermometer carried out for 2 weeks after that. With perform the same experiment repeatedly, he found the ice melts on the same calibration mark on the thermometer. He found a point similar to the calibration at the boiling of water vapor (when experiments were performed with high accuracy, the variation seen with variations in atmospheric pressure). When he remove the thermometer from the water vapor, the height of the mercury down slowly. This related to the rate of cooling (and the expansion of the glass tube). Air pressure affect the boiling point of water. Celsius claims that height of mercury as water evaporation is proportional to the height of the barometer. When deciding to use the Celsius temperature scale itself, he determine the boiling point at 0 ° C (212 ° F) and freezing at 100 ° C (32° F). One year later Frenchman Jean Pierre Cristin proposed version of the inverse Celsius scale the freezing point at 0 ° C (32 ° F) and boiling point at 100 ° C (212 ° F). He named it Centrigade. In the end, proposed the Celsius thermometer calibration method as follows: 1. Place the thermometer in the water cylinder and mark the point of pure melts when fluid in the thermometer is stable. This is the freezing point of water.
read. A special type of thermometer mercury, called the maximum thermometer, working with the valve on the neck of the tube near the bulb. When the temperature rises, the mercury is driven upwards through the valve by the force of expansion. When the temperature drops of mercury retained on valve and can not return to the bulb make the mercury remains in the tube. The reader can then read the maximum temperature during the time predetermined. To restore its function, the thermometer should be swung hard. This thermometer medical thermometer-like design. Mercury will freeze at a temperature of 38.83 ° C (37.89 ° F) and can only be used at temperatures above it. Mercury, unlike water, does not expand when frozen so it does not break the glass tube, making it difficult observed when it freezes. If the thermometer contains nitrogen, the gas may flowing down into the column and trapped there when the temperature rises. If
This happens thermometer can not be used until the return to initial conditions. To avoid this, the mercury thermometer should be inserted into the a warm place at temperatures below 37 ° C (34.6 ° F). In areas where the maximum temperature is not expected to rise above 38.83 ° C (37.89 ° F) thermometer that uses a mixture of mercury and thallium may be used. This thermometer has a freezing point of 61.1 ° C (78 ° F). Mercury thermometers commonly use the Celsius temperature scale and Fahrenhait. Anders Celsius Celsius scale formulation, presented in its publication "The Origin of the Celsius temperature scale" in 1742. Celsius used two important points on the scale: temperature when the ice melts and the temperature
evaporation of water. This is not a new idea, since Isaac Newton first worked with
something similar. Celsius temperature measurements using the melting temperature and
instead of freezing temperatures. Experiment to get a better calibration on the Celsius thermometer carried out for 2 weeks after that. With perform the same experiment repeatedly, he found the ice melts on the same calibration mark on the thermometer. He found a point similar to the calibration at the boiling of water vapor (when experiments were performed with high accuracy, the variation seen with variations in atmospheric pressure). When he remove the thermometer from the water vapor, the height of the mercury down slowly. This related to the rate of cooling (and the expansion of the glass tube). Air pressure affect the boiling point of water. Celsius claims that height of mercury as water evaporation is proportional to the height of the barometer. When deciding to use the Celsius temperature scale itself, he determine the boiling point at 0 ° C (212 ° F) and freezing at 100 ° C (32° F). One year later Frenchman Jean Pierre Cristin proposed version of the inverse Celsius scale the freezing point at 0 ° C (32 ° F) and boiling point at 100 ° C (212 ° F). He named it Centrigade. In the end, proposed the Celsius thermometer calibration method as follows: 1. Place the thermometer in the water cylinder and mark the point of pure melts when fluid in the thermometer is stable. This is the freezing point of water.
2. In the same way mark the point at which the liquid is stable when thermometer placed in boiling water vapor.
3. Divide the length between two points with 100 parts of the same small. Dots was added in a calibration average but both are very depending on air pressure. Currently, three dots are used instead of water (The third point occurs at 273.16 kelvins (K), 0.01 ° C). NOTE: All
heat transfer stops at 0 K, but this temperature is still impossible to achieve because the physics is still not possible to stop the particles. Today mercury thermometers are still widely used in the fields of meteorology, but the fields hand use Another less, because mercury permanently very toxic to the system is fragile and few countries progress have condemned its use for medical purposes. Some companies using a mixture of gallium, indium, and tin (galinstan) instead
mercury.
heat transfer stops at 0 K, but this temperature is still impossible to achieve because the physics is still not possible to stop the particles. Today mercury thermometers are still widely used in the fields of meteorology, but the fields hand use Another less, because mercury permanently very toxic to the system is fragile and few countries progress have condemned its use for medical purposes. Some companies using a mixture of gallium, indium, and tin (galinstan) instead
mercury.
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