Mercury thermometers are based on the principle that liquids expand when heated and contract when cooled . So, when the temperature increases, the mercury expands and rises up the tube and when the temperature decreases it contracts and does the opposite.
What is principal of thermometer?
Thermometers are based on the principle of expansion in liquids . When temp increases mercury inside the thermometer expands to give reading of temperature.
What is the working principle of thermometer?
A thermometer works on the principle of thermal expansion .
What is the best principle of thermometer?
Answer: The thermometer works on the principle of “zero'th law of Thermodynamics” . This law states that if two bodies are in thermal equilibrium with another body, then they must also be in thermal equilibrium with each other.
Who uses thermometer?
Meteorologists use thermometers to find out how hot it is or if it's below freezing. Doctors use thermometers to check your body temperature — a very high or low body temperature means you're sick.
What is the working principle of hydrometer?
A hydrometer is an instrument used to determine specific gravity. It operates based on the Archimedes principle that a solid body displaces its own weight within a liquid in which it floats . Hydrometers can be divided into two general classes: liquids heavier than water and liquids lighter than water.
Who invented thermometer?
The more modern thermometer was invented in 1709 by Daniel Fahrenheit . It was an enclosed glass tube that had a numerical scale, called the Fahrenheit scale. The early version of this thermometer contained alcohol and in 1714 Fahrenheit developed a mercury thermometer using the same scale.
What are the advantages of mercury thermometer?
- It is a good conductor of heat and hence, can measure even high temperatures.
- It gives results quickly – has a fast response time.
- It expands linearly and less than alcohol and any other liquid.
- It is more durable than alcohol thermometer because mercury does not evaporate easily.
Which law is used in thermometer?
The Zeroth Law of Thermodynamics defines temperature and makes thermometers possible. For a thermometer to be useful, though, it must be first calibrated. All other basic units of measure, e.g., for length, mass, time, etc., are each defined according to a precise standard.
Is it illegal to have a mercury thermometer?
Those days have passed. Since 2001, 20 states have banned mercury “fever thermometers” for medical use , and regulations tighten every year. ... But as of today the federal government has more or less killed the mercury thermometer in the United States—NIST has announced it will no longer calibrate mercury thermometers.
What are the two types of thermometer?
- Digital thermometers. ...
- Ear (or tympanic) thermometers. ...
- Infared thermometers. ...
- Strip-type thermometers. ...
- Mercury thermometers.
Which type of thermometer is most accurate?
Digital thermometers are the most accurate way to take body temperature. There are many types, including oral, rectal, and forehead, plus many that are multifunctional. Once you decide on the type of thermometer you want, you can think about design, extra features, and price.
What is range of normal body temp?
The average normal body temperature is generally accepted as 98.6°F (37°C). Some studies have shown that the “normal” body temperature can have a wide range, from 97°F (36.1°C) to 99°F (37.2°C) .
How can we use thermometer in our daily life?
– To measure the outdoor temperature . – To measure body temperature during a physical exam at the doctors. – To measure body temperature when someone is ill to determine if he/she has a fever. – To measure the temperature of an oven.
Who uses hydrometer?
The specific gravity of a liquid is the density of that liquid divided by the density of water (in the same units). A hydrometer accomplishes this by measuring the amount of water it displaces. Hydrometers are commonly used by winemakers to determine the sugar content of wine , and they're also used in soil analysis.
Why mercury is used in hydrometer?
Description: A hydrometer is an instrument used to measure the specific gravity of a liquid – the ratio of the density of the liquid to the density of water. ... Purpose of the Mercury: The mercury was used in hydrometers as a weight so that the device would be buoyant in a liquid solution .
