Thermometer is made with the thick glass externally. At the middle capillary tube is kept. A glass tube is closed at one end and another is flattened. This is called bulb. The bulb of thermometer is made with thin glass to enter the heat from outside. The bulb is filled with mercury or alcohol. When bulb is in contact with the hot object then volume of liquid inside it expands and level of liquid increases. In this way, thermometer shows the temperature o substance.
A thermometer has a glass tube sealed at both ends and is partly filled with a liquid like mercury or alcohol. As the temperature around the thermometer's bulb heats up, the liquid rises in the glass tube. ... When it is hot, the liquid inside the thermometer will expand and rise in the tube.The operating principle of a thermometer is quite simple. A known measure of liquid (mercury, alcohol, or a hydrocarbon-based fluid) is vacuum-sealed in a glass tube. The liquid expands or contracts when air is heated or cooled.
- Carefully place the tip of the thermometer under your child's tongue.
- With your child's mouth closed, leave the thermometer in place for about 1 minute until you hear the “beep”
- Remove the thermometer and read the temperature.
A thermometer is an instrument that measures temperature. It can measure the temperature of a solid such as food, a liquid such as water, or a gas such as air. The three most common units of measurement for temperature are Celsius, Fahrenheit, and kelvin. The Celsius scale is part of the metric system.The way a thermometer works is an example of heating and cooling a liquid. When heated, the molecules of the liquid in the thermometer move faster, causing them to get a little further apart. ... When cooled, the molecules of the liquid in the thermometer move slower, causing them to get a little closer together.