Mercury thermometer is expanding a thermometer

Mercury thermometer is expanding a thermometer, mercury freezing point is: - 39 ℃, boiling point is: 356. 7 ℃, which is used to measure - 39° C ~ 357° C within the range of temperature, it can only be as on-site monitoring instrument. Use it to measure temperature, not only is simple and intuitive, but also can avoid external remote transmission error of the thermometer. Using temperature time, first to see its range ( Measuring range), Minimum degree value, and then see it, that is, the value of the each represents a small grid. To select the appropriate thermometer to measure the temperature of the object to be tested. When measuring the vacuole of the thermometer should contact with fully object to be tested, and the glass bulb without touching the side or bottom of the object to be tested; Thermometer readings, don't leave the object under test, and the line of sight of the eyes should h flat with a thermometer. 1, before the use should check ( More than standard liquid temperature comparison method may be used for calibration or more advanced precision thermometer) 。 2, are not allowed to use temperature more than the biggest scale value of the thermometer measurements. 3, thermometer have thermal inertia, after should reach a steady state in thermometer readings. Reading should be in the highest temperature on convex curved surface tangent to read, looking directly at them. 4, mercury thermometer should be measured working medium with vertical or inclined shaped the direction of flow. 5, mercury thermometer, mercury broken happen often, eliminating method is: ( 1) Cold repair method: put thermometer temperature bag into the dry ice and alcohol mixture ( Temperature shall not exceed - 38℃) Cold, all make the mercury in the capillary contraction at the temperature measurement in the package. （ 2) Hot fix method: insert the thermometer slow temperature slightly higher than the upper limit in the constant temperature trough, the mercury broken part and the mercury column, and then slowly remove the thermometer and cooling to room temperature in the air.