Definition - What does Liquid-in-Glass Thermometer mean?
A Liquid-in-Glass Thermometer is a glass capillary tube having a liquid-filled bulb present at one end. This device is used for measuring temperature due to its accuracy and the fact that it does not require any other equipment except the human eye. An example of the Liquid-in-Glass Thermometer is the mercury thermometer which been in use since early 18th century. Mercury, the liquid in the thermometer, is enclosed in a sealed glass bulb that expands into a fine bore present in the stem of the thermometer. A scale is etched along the stem of the thermometer that is used for reading the temperature.
Petropedia explains Liquid-in-Glass Thermometer
The Liquid-in-Glass Thermometer is a type of a thermometer used to measure temperature. The thermal expansion of the liquid is the principle used to measure the temperature in the thermometer. When the temperature increases, the liquid expands and then rises in the capillary tube in the thermometer. The temperature can be noted by the level of liquid with the help of a scale etched in the outer side of the glass. The Liquid-in-Glass Thermometer consists of a bulb, a stem, a temperature scale, a reference point, an inert gas and a working point. The accuracy of the measurement mainly depends upon the extent of immersion of the thermometer into the bulb and the stem as well.