Thermometers don't have to use Mercury.
But its thermal expansion, resistance to evaporation, and that it's a liquid in the most common temperature range on Earth makes it a tempting choice. Unfortunately, it's quite toxic, so manufacturers are moving to other, more environmentally friendly materials.
Mercury rises in a thermometer when the temperature increases because mercury expands as it heats up. This expansion of the mercury column inside the thermometer is used to measure the temperature of the surrounding environment.
The liquid in a clinical thermometer is called mercury. It is used to measure body temperature by expanding and rising within the thermometer.
Mercury in a Mercury thermometer is typically silver in color.
In a mercury thermometer, the mercury expands when it is heated, causing it to rise in the thermometer's narrow tube. This increase in volume is a physical property of mercury known as thermal expansion. The height of the mercury column in the thermometer is then used to measure the temperature.
Frequently thermometers filled with an alcohol; but also thermometers with mercury, with thermoresistance, thermocouples, etc.
A mercury thermometer is used to measure temperature.
Mercury and alcohol
Mercury rises in a thermometer when the temperature increases because mercury expands as it heats up. This expansion of the mercury column inside the thermometer is used to measure the temperature of the surrounding environment.
A mercury thermometer can go down to -30 deg C
mercury
toxic poison
The liquid in a clinical thermometer is called mercury. It is used to measure body temperature by expanding and rising within the thermometer.
Mercury in a Mercury thermometer is typically silver in color.
In a mercury thermometer, the mercury expands when it is heated, causing it to rise in the thermometer's narrow tube. This increase in volume is a physical property of mercury known as thermal expansion. The height of the mercury column in the thermometer is then used to measure the temperature.
iodine and Mercury
Mercury
It could be used to do this - it is capable of doing it. However, Mercury is poisonous and a mercury thermometer is made out of fragile glass. Thus the danger that the thermometer would break releasing mercury into the milk (which would be for a person to drink) means that a mercury thermomiter is not the temperature sensor to use in this instance.