Temperature is the degree of hotness and coldness of an object.Temperature is the measure of coldness and hotness expressed in terms of any scales ,which are named as :
Celsius Fahrenheit Kelvin
A high temperature of an object tells us that it is very hot whereas a low temperature of the object tellsus that is quite cold . So, the temperature is expressed in the unit if [degree Celsius].
Temperature is a measure of average kinetic energy per molecule in a substance .It is different from heat,although the two quantities are related.
Temperature can be feel but we can not touch it .
Temperature is a measure of how hot and cold something is specifically a measure of average kinetic energy of object.
Definition
Temperature refers to how cold or hot an object is called temperature.
In other words, Temperature is proportional to the average random Kinetic Energy of ideal gases .
How to measure temperature?
A device which is used to measure the temperature of a body is thermometer.Thermometer is used to get the value of temperature. Temperature can be expressed in the unit of degree Celsius:(which is written in short form as °C).Thermometer is a long ,narrow, uniform glass tube is called stem. Thermometer is the instrument to used for measuring temperature. They are a thin glass tube filled with a small amount mercury.The normal temperature of human body is 37°C.
Thermometer can also be used to measure the atmospheric temperature and temperature during chemical reactions.
Substance which show a change with temperature can be used as thermometric material.
Liquids also expand on heating and are suitable as thermometric materials.
Properties of Thermometeric material:
It should be visible.
It should have uniform thermal expansion.
It should have low freezing point.
It should have high boiling point.
It should not wet glass.
It should be a good conducters of heat.
It should have a small specific heat capacity.
Liquid-in-Glass Thermometer
It has a bulb with a long capillary tube.
A suitable liquid is filled in the bulb. When the bulb contacts as hot object, the liquid in it expand and rises.
Why mercury is used as a thermometric material?
Mercury freezes at -39 degree Celsius.
Mercury boils at 357 degree Celsius.
It has all the thermometric properties .
It is normally used in the range from -10 degree Celsius to 150 degree Celsius.
Lower and upper Fixed points
Lower fixed point:-
It shows position of liquid in thermometer when placed in ice.
Upper fixed point:-
It shows position of liquid in thermometer when it is placed in steam.
Types of temperature scale are as follows:
types-of-temp
Absolute zero
The temperature on Kelvin scale is called absolute temperature.The temperature of -273 °C at which the pressure and volume of the enclosed gas becomes zero is called absolute zero. It is the lowest possible temperature.
Degree Celsius Scale : The Celsius temperature is a commonly used system in international temperature scale (SI).It is denoted as°C.and read as degree Celsius or Celsius .For instance,20°C will be read as twenty degree Celsius.
Fahrenhit Scale : Fahrenhit is a temperature which based on the freezing point of water at 32°F and the boiling point of water at 212°F. It is introduced by the Physicist Daniel Gabriel Fahrenheit in 1720 A.D.This scale uses the symbol °F.
Kelvin Scale : Kelvin scale is the most commonly used temperature scale in science . it is an absolute temperature scale defined to have 0 K at the lowest possible temperature, called absolute zero.It is denoted as K. For instance ,100k will be reached as hundred Kelvin.
Conversion of Temperature
From Celsius to Kelvin Scale.
From Kelvin to Celsius Scale.
From Celsius to Fahrenheit Scale.
From Fahrenheit to Celsius Scale.
Types of Thermometer
Clinical Thermometer.
Digital Thermometer.
Laboratory Thermometer.
Clinical thermometer
Clinical thermometers are used to measures the human body temperature.
Clinical thermometer
The thermometer used by us or doctors to measure the body temperature when we have fever is a clinical thermometer.
The scale which is used to measure the temperature is known as Celsius scale denoted by °C or Fahrenheit denoted by °F.
It reads the temperature from 35°C to 42°C or from 94°F to 108°F.
Digital thermometer
Digital thermometer are an advance to the existing clinical thermometers.
Digital thermometer
Due to high toxicity of the mercury present in clinical thermometer and difficulty in its disposal in cases when the thermometer breaks digital thermometers are manufactured which can measure the accurate temperature without the use of mercury . Because it is a dangerous molecule.
Digital thermometers are not made up of mercury and hence safe to use.
Laboratory thermometer
Laboratory thermometer Is used to measure the temperature of the things other then human body .
Laboratory thermometer
Clinical thermometer can not be used for measuring the temperature of any object other except human body.
It is used to measure the temperature in school or other laboratories for scientific purpose as they measure temperatures to a range higher than clinical thermometers.
One such thermometer is known as the laboratory thermometer is known as the laboratory thermometer with a scale generally ranging from -10 °C to 110 °C.
Laboratory thermometer has a long stem with a silver bulb at the end unlike clinical thermometer.
What is a temperature sensor?
A temperature sensor is type of sensor which tells the high temperature of an object .It tells us that it is very hot whereas a low temperature of the object tells us that it is quite cold. So,the temperature is expressed in the unit of degree Celsius.
A temperature sensor is an device RTD (Resistance Temperature Detectors) or a thermocouple, that collects the data about temperature from a particular source and converts the data into a understandable form for a device or an observer.
Types of temperature sensor
Thermocouples
Thermistors
Infared sensors
Semi conductors
Thermocouples
The thermocouple is a sensor used to measure temperature .It is a sensing device .Thermocouple are made with two different metals which are joined together at the end to form a junction .The thermocouples “SEEBEK EFFECT”.
Thermocouples
Thermistors
The thermistor is a temperature sensitive device or Resistance whose electrical resistance change in body temperature. These are the materials which are sensitive i.e their resistance changes very rapidly with change in temperature.
There are generally two types:
PTC : Positive temperature cofficient.
NTC : Negative temperature coffcient
It is made by Semi–Conductors Materials .
Thermistors
Infrared sensors
Infrared sensors are the electric instrument which are used to certain characteristics of its surroundings .Infrared sensors are widely used in motion detectors. It work with radar technology and they both emit and receive infrared radiation.
infrared-sensor
Semi-conductors
Semi-conductors are those materials which act as a insulator at zero Kelvin and as Conductors as room temperature.
For example: Silicon ,Germanium etc .
semi-conductor
Note: They do not conduct at low temperature but as the temperature increases, they start conducting.
Types of semi-conductors
Intrinsic Semi-conductors
Extrinsic Semi-conductors.
Intrinsic Semi-conductors
Pure Semi-conductors are known as intrinsic Semi-conductors. It is also called undoped semiconductor or i-type semi –conductor ,is a pure semiconductor without any significant dopant species persent.
For Example: Si, Ge.
Extrinsic Semi-conductors
These are made by doping same impurity to the pure form of Semi-Conductors.
These are of two types:
P- type semi-conductors.
n- type semi-conductors.
P –type Semiconductor
When a trivalent impurity is added in a pure form of semi-conductors then semi-conductors is so formed are known as P-type Semi-conductors .It is also known as acceptor type Semi-conductor.
2. n-type Semi-conductor
When a Pentavalent impurity is added in a pure Semi-conductor then a Semi-conductor. So Formed as known as n-type semi-conductors. It is also known as doner type semi-conductors.
Conclusion
Temperature is a measure of average Kinetic energy per molecule in a substance.
Kinetic energy is a type of energy associated with motion of a object.
Temperature is a Physical quantity that express hot and cold.
Temperature can be measured by a device called thermometer .
Clinical thermometer 2.Digital thermometer 3. Laboratory thermometer.
Temperature Measurement is a process of measuring temperature by using different temperature scale which are follows as : Celsius scale ,Fahrenheit scale ,Kelvin scale .
A temperature sensor is type of sensor which tells the high temperature of an object .It tells us that it is very hot whereas a low temperature of the object tells us that it is quite cold. So, the temperature is expressed in the unit of degree Celsius.