what liquid is in a thermometer

The liquid in a thermometer can vary depending on the type of thermometer. Mercury thermometers, which are now banned in many countries due to the potential dangers of mercury, use a small amount of liquid mercury to measure temperature. However, other types of thermometers have been developed that use different liquids. One common type of thermometer is the alcohol thermometer, which uses a type of alcohol, such as ethanol or isopropanol, as the liquid. The liquid is dyed red to make it easier to read the temperature. Alcohol thermometers work on the principle that the volume of liquid in the thermometer changes with temperature. As the temperature increases, the volume of liquid in the thermometer increases, causing the liquid to rise in the tube. In general, the red liquid used in alcohol thermometers is not considered to be dangerous. Unlike mercury, alcohol is not toxic and is not harmful if ingested or inhaled in small amounts.