How to make the fracture of mercury mercury thermometer back to normal?

Mercury thermometer is the thermometer is known to all, but in use will happen some problems. Some people will find that the mercury in the mercury thermometer to failure, can not be normal temperature, then use what method can let it return to normal? Let fracture of mercury mercury thermometer back to normal there are two ways, one is cold repair method, using the method is to insert the thermometer temperature pack dry ice and alcohol mixture ( Remember that temperature shall not exceed - 38℃） Cold, all make the mercury in the capillary contraction at the temperature measurement in the package. Take out again slowly returning to room temperature. The second method is the hot repairing method, first insert the thermometer slow temperature slightly higher than the upper limit of thermostatic bath, broken part the mercury and the mercury column, and then slowly remove the thermometer and cooling to room temperature in the air. If the two methods can't let mercury returned to normal, so it is for this thermometer is broken, can't use. Warm prompt: mercury thermometer at the time of use should pay attention to the following matters: ( 1) Before the use should check; ( 2) Not allowed to use temperature more than the biggest scale value of the thermometer measurement values; ( 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 measured material should be with vertical or inclined shaped the direction of flow.