Which liquid is used in liquid-in-glass thermometer?
mercury
The fluid used in the thermometer is normally either mercury or colored alcohol contained within a bulb and capillary tube, as shown in Fig. 14.18A. As the temperature rises, the fluid expands along the capillary tube and the meniscus level is read against a calibrated scale etched on the tube.
What is liquid-in-glass thermometer in physics?
It consists of mercury as a liquid filled in a glass tube. On the body of the glass tube, calibrated marks are provided which facilitates the reading of temperature. A bulb is formed at one end of the thermometer which contains the largest part of mercury.
Where is liquid-in-glass thermometer used?
Liquid-in-glass thermometers are mainly employed in the Navy and Marine Corps in different configurations. They are also applied in meteorological and oceanographic applications, where they are generally calibrated by graduations eternally engraved into the glass.
How do you increase the sensitivity of a liquid in a glass thermometer?
So if you want to increase the sensitivity of a liquid-in-glass thermometer (resulting in a larger rise in the column of liquid for each degree Celsius), increase the volume of the bulb. Note however, that a larger bulb will decrease the range of temperatures that can be measured.
Why does liquid in the thermometer rise when?
1. The liquid in the thermometer goes up when the thermometer is heated because heating makes the alcohol molecules of the liquid move faster. The extra speed of the molecules competes with their attraction for one another and causes them to move slightly further apart.
How does a liquid thermometer work?
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. This results in movement up the thermometer.
What is liquid thermometer used for?
In a mercury thermometer, a glass tube is filled with mercury and a standard temperature scale is marked on the tube. With changes in temperature, the mercury expands and contracts, and the temperature can be read from the scale. Mercury thermometers can be used to determine body, liquid, and vapor temperature.
How does bulb size affect thermometer?
The amount of mercury or alcohol that expands into the capillary tube depends on the volume of the bulb. The bigger the bulb, the more liquid forced into the capillary. This decreases the range, making the thermometer more sensitive to change in temperature.
What is the principle behind the liquid thermometer?
Liquid-in-glass thermometers are based on the principle of thermal expansion of substances. A liquid in a glass tube (called a capillary) expands when heated and contracts when cooled. A calibrated scale can then be used to read off the respective temperature that led to the corresponding thermal expansion.
Why the liquid in the thermometer goes down when cooled?
When cooled, the molecules of the liquid in the thermometer move slower, causing them to get a little closer together. This results in movement down the thermometer.
How do liquid thermometers work?
How does a thermometer work physics?
These liquid thermometers are based on the principal of thermal expansion. When a substance gets hotter, it expands to a greater volume. Nearly all substances exhibit this behavior of thermal expansion. It is the basis of the design and operation of thermometers.