What is constant volume thermometer?
A constant volume gas thermometer ususally consists of a bulb filled with a fixed amount of a dilute gas which is attached to a mercury manometer. The manometer is used to measure variation in pressure. This thermometer works on the principle of Law of Gay-Lussac.
What is the working principle of the constant volume gas thermometer?
A constant volume gas thermometer works on the principle of Charle’s law. Note: Charle’s law can also be defined as when the pressure remains constant, then the volume of the gas increases or decreases by the value 1273.15 of its volume at 00C for each 10C rise or fall of temperature.
What is the working principle of thermometer?
thermal expansion
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.
What is the formula for calculating constant volume thermometer?
In its modern form, Charles’ law states that for a fixed mass of gas at constant pressure the volume is proportional to the absolute temperature, or V/T = constant. These two laws combine to give PV/T = constant.
What are the advantages of constant volume gas thermometer?
Advantages of constant volume Gas thermometer:-)
- As the expansion of gas is large, so the Gas thermometer are very sensitive.
- The gas expand uniformly and regularly over a wide range of temperature .
- The expansion coefficient of all gases is nearly the same, so thermometer using different gases give same reading.
Why mercury is used in thermometers?
Mercury is the only one in liquid state at room temperature. It’s used in thermometers because it has high coefficient of expansion. Hence, the slightest change in temperature is notable when it’s used in a thermometer. It also has a high boiling point which makes it very suitable to measure higher temperatures.
Where is a constant volume gas thermometer used?
A constant – volume gas thermometer is used to measure the temperature of an object . When the thermometer is in contact with water at its triple point (273K) the pressure in the thermometer is 8.50×104Pa . When it is contact with the object the pressure is 9.650×104Pa .
What are the merit and demerit of a constant volume gas thermometer?
Advantage: There is no difference in temperatures recorded on two different constant volume gas thermometers. Hence, it is very accurate. Disadvantage: Constant volume gas thermometer is bulky instrument. Hence, it is not easily portable.
What is the advantage and disadvantage of thermometer?
A thermometer comparison
| advantages | disadvantages |
|---|---|
| cheap | display is harder to read |
| durable | does not work below -39 C (Hg freezing pount) |
| accurate | cannot be used for thermograph |
| easily calibrated | slow response |