How do you know glass rod thermometer readings and repair?

Glass rod thermometer can be found everywhere in our life, how do you know the glass rod thermometer should be reading the fix? Today let's say the two problems. First is the problem of reading, in general, when reading the scale and Numbers in the middle of the triangular, triangular place is a magnified effect, showed that the temperature of the reading is correct. In the glass rod thermometer use after a period of time, we often find thermometer will exist in different levels of mercury breakdown phenomenon. This time you should adopt the appropriate way to repair it. For the moment, relatively simple mercury thermometer repair methods are divided into cold state and hot fix method two kinds. A, cold repair method is: will the temperature of the thermometer package (in a mixture of dry ice and alcohol liquid Temperature more than 38 ℃ below zero) For cold, let all fracture of mercury in capillary recycling to the temperature measurement in the package. Second, hot fix method: put the side subsistence of the thermometer in the slightly higher than the measurement limit temperature of the liquid, let the part of the mercury column fracture reconnect, then slowly thermometer will take out, in the air cooling to normal temperature.