Thermometer Calibration

Introduction to thermometer calibration:

we have read that on touching an object,if heat flows from our hand to the object,the object appears cold to us,while if heat flows from object to our hand,the object is said to be hot.but this method of finding the temperature is not reliable and not scientific.For scientific purpose,we need an accurate measurement of temperature.The instrument used for measuring the temperature is called a THERMOMETER.

Please express your views of this topic Formula for Centripetal Acceleration by commenting on blog.

There are several types of  thermometer such as liquid thermometer,platinum resistance thermometer ,thermocouple thermometer,constant  volume gas thermometer,vapour pressure thermometer,magnetic thermometer and radiation thermometer.The choice of thermometer depends on the range of temperature to be measured,the accuracy required and the physical conditions of the substance of which temperature is to be measured.

Important note:The substance used in a thermometer must have some characteristic property that changes with temperature.Such a property is called the thermometric property of the working substance.


About thermometer calibration


The calibration of a thermometer  involves fixing of two points on it-one lower fixed point and other upper(or higher) fixed point and then dividing the interval between the lower and upper fixed points into a convenient number of  equal parts.Each part is called a degree.The fixed points are chosen in such a way that they can easily be obtained.

Lower and higher(or upper) fixed points

The melting point of pure ice at one atmospheric pressure(ice point) is taken as the lower fixed point. The boiling point of pure water at one atmospheric pressure (the steam point) is taken as the higher(or upper) fixed point.

Dividing the interval between the two fixed points

The interval between the lower and upper fixed points is divided in a suitable number of equal parts depending upon the scale of  temperature.Each interval is called a degree.For the celcius(or centigrade) scale,the interval is divided in one hundred equal parts,and for the Fahrenheit scale, the interval is divided into 180 equal parts.

Is this topic Formula for Momentum hard for you? Watch out for my coming posts.

Uses of thermometer


Thermometer is used

To measure the temperature of a liquid and

To measure the patient's body temperature.