Question

The kink (constriction )is used in a clinical thermometer. why?

Answer 1

Answer:

When taking someones temperature, the mercury rises up the column and stabilises at body temperature. When it is then removed from the mouth or which ever oriffice it has been inserted into, the mercury would immediately start to contract down the column and a false reading would be obtained. The constriction in the column prevents this and holds the reading. This is why you need to shake the thermometer after taking a reading, to get the mercury held in the column past the constriction and back into the bulb.