Structure of laboratory thermometer
Thermometers are of different types and have different uses.
Clinical thermometers are used for measuring body temperature.
Laboratory thermometers are used for measuring the temperature of different objects.
We will learn about laboratory thermometers in detail.
In a laboratory, we use a thermometer to measure the temperature of gases, liquids and solids for accuracy in the experiments.
These thermometers use mercury in them. Thermometers work on the principle of thermal expansion.
Mercury will expand according to the heat given to it. The more the heat, the more is the expansion.
The mercury is in the round bulb. When it is heated, it expands into the long cylindrical construction.
This length will be measured as the degree of heat called temperature. Different scientists have a different approach towards measuring this length.
The different scales of temperature are Celsius, Fahrenheit or Kelvin. Each unit is named after the scientist who proposed it.
Celsius(
o
C
) is the most common unit of temperature in the world. This is used in clinical thermometers.
Fahrenheit(
0
F
) is mostly used in the US and Kelvin(
K
) is called the absolute scale of temperature, used in laboratories for accuracy.
The range of measurement of the temperature of the laboratory thermometer is
−
1
0
o
C
to
1
1
0
o
C
.
Clinical Thermometer
Doctors use a kind of thermometer to measure the temperature of humans.
We can put them under the tongue or under the armpits. They are clinical thermometers.
A clinical thermometer has a kink in it. It is a sharp bending in the thermometer. It prevents the rapid fall of mercury after measuring temperature.
The kink gives us enough time to record the measurement. Kink is absent in laboratory thermometer.
These thermometers use Celsius(
o
C
) scale. The normal temperature of an average human is
3
7
o
C
.
But nowadays we also use electronic thermometers or digital thermometers. This type of thermometer is used in the same way as the mercury thermometer.
We also have advanced infrared thermometers as clinical thermometers. They can measure temperature from a distance. They are mostly used for babies.
Difference between laboratory and clinical thermometer.
Clinical thermometers measure the temperature of human bodies and laboratory thermometers measure the temperature of all other bodies.
Human body temperature can fluctuate between 35˚C to 42˚C only. So, the clinical thermometers have a temperature range of 35˚C to 42˚C.
The range of measurement of the temperature of the laboratory thermometer is
−
1
0
o
C
to
1
1
0
o
C
.
Revision
Thermometer is used to measure temperature of any body or any object. Temperature is measured in Celsius, Fahrenheit or Kelvin.
Clinical thermometers measure the temperature of human bodies and laboratory thermometers measure the temperature of all other bodies.
The clinical thermometers have temperature range of 35˚C to 42˚C. Temperature in a laboratory thermometer ranges from -10˚C to 110˚C.
Kink is a sharp bending in the thermometer. The presence of kink prevents rapid fall of mercury after measuring body temperature.
The End