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Thermometer in small knowledge Time :2009-07-2 Click: 3 |
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thermometer is the use made of the principle. We have seen the thermometer outside is a two-tier glass tube, which in a thin glass tube containing a red liquid; in the same conditions, the degree of thermal expansion of liquid than solid large. Therefore, when the temperature changes, the glass surface will increase or decrease; as a result of very small diameter glass tube, the change in liquid volume will show a high degree of apparent change; from the corresponding scale on the glass can be learned the temperature of objects. From an early age the thermometer, the temperature of the industry are used in large-scale thermometer produced in accordance with the principle of. Thermometer commonly used liquid mercury, kerosene and alcohol.
Glass thermometer is the fluid temperature will be felt filling the glass bubbles and glass capillary with welding, at capillary-scale or scale plate, the temperature inside the capillary column surface may be the location of the thermometer read out device.
Glass thermometers are commonly used in a variety of classifications.
According to the use of industrial glass thermometer into the glass thermometer and experimental, which means industrial glass thermometer is installed in the project facilities (such as machinery, pipes and containers) on the glass thermometer, laboratory glass thermometer is the use of scientific experiments in glass thermometer, the experiment glass thermometer into the basis of their precision temperature measurement accuracy and common glass thermometer glass thermometer.
According to the temperature and the use of liquid into the glass mercury thermometer and organic liquids (such as kerosene, ethanol, toluene, etc.) glass thermometer.
Divided in accordance with standard type glass thermometer and stick-style glass thermometer. Standard glass thermometer is the scale of capillary and sealed in a glass casing plate, the capillary temperature and the lower end of bubble fusion of glass thermometer, stick-style glass thermometer is the pores of glass with temperature and the bubble-phase welding, glass stick or penetrate the surface, etching printed color of the glass thermometer scale.
Based on the way into full-immersion-style glass thermometer Baptist and Baptist-style glass thermometer Board. Immersion-style glass thermometer is the thermometer of the temperature of the liquid column has been immersed in media, so that the surface of the liquid column surface and the media in the same plane as far as possible, the glass thermometer, glass thermometers Baptist Board refers to the required depth of immersion thermometer under test medium temperature glass thermometer. Full-immersion thermometer glass thermometer should be in the back of subscript the "Baptist" and the Baptist Board standard thermometer immersion depth should be marked, Baptist Board rod thermometer should be immersed in the place provided for the permanent marking or etching a submerged line. Board Baptist glass thermometer in the use of liquid column to be exposed to show its correction, the glass thermometer immersed in the dip for the Board to use his column to show the correction.
Glass thermometers have a small number of 30 terms, such as fluid temperature, hot temperature, capillary, enamel belt scale plate temperature owner, his column, the middle of the bubble, security bubble, the expansion chamber, Capping scale line, scale, the main scale, Des scaling, sub-grid, on the [next] limit, the maximum [lower] calibration line, show engraved lines, immersion line, test points, showing the value, that value error and correct the value of zero on the rise, against a lower value. Here a few extracts from the need to pay attention to the terminology.
Against the appreciation of: thermometer with an increase in the use of time, due to viscous flow of glass into the effects of temperature so that the bubble volume reduced, the thermometer showing against the rising values of a permanent phenomenon, and its temperature rise as against the appreciation of the value.
Against a lower value: the thermometer in the measurement of high temperature to room temperature after the cold at first, due to the flexibility of glass structure, the impact of more than efficiency, so that the bubble temperature and volume can not be restored to the use of state, causing the thermometer showed a temporary decline in value, the decrease of temperature as low down the value of zero.
Indication stability: in the time and temperature with a thermometer showing the value of maintaining stable performance. Commonly used method of determination of the provisions of the thermometer against the dollar and against the lower value in order to study the stability of its indication. |
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