A thermometer, and the difference between ordinary thermometer

Bubble, mercury thermometer consists of glass shell, glass, capillary, scale and unit symbols. Compared to ordinary thermometer, its glass bubble volume is bigger, glass tube diameter finer, and mercury is a liquid metal, metal tend to react to temperature quickly, for the tiny temperature changes can show a longer mercury change, therefore more accurate measurement results. Thermometer above the glass bulb containing mercury that did have a very thin mouth, inflation by reducing measuring temperature when mercury rises into the glass tube, reading thermometer thermometer to leave the human body, mercury meets cold contraction, mercury too late return the glass bulb, in mouth disconnect, still indicate the original temperature, so the thermometer reading can leave the body; And mercury surface tension, contact with the air like half ball, can reduce the error of observation. While ordinary thermometer can't leave the reading of the object to be tested, used by other liquid ( Such as kerosene, alcohol, etc. ) Surface tension is small, more than air-contact surface concave, unfavorable to observe.