3. Introduction of Temperature Measurements
Types
Significance
Applications
4. The actual measurement of temperature is vital across
abroad spectrum of human activities.
Including industrial processes (e.g. making steel
manufacturing)
Monitoring (in food transport and storage)
Heath and safety
In fact ,in almost every sector, temperature is one of the
key parameters to be measured.
5. One of the differences between temperature and
other physical concepts, such as mass or length , is
that it is subjective.
Different people will have different perceptions of
what is hot and what is cold.
To make objective measurements, we must use
thermometer in which physical property of a
substance changes with temperature in a reliable and
reproducible way.
6. Temperature is a measure of the thermal energy in
the body .
Normally measured in degrees [℃] using one of
the following scales.
1. Fahrenheit
2. Celsius or Centigrade
3. Kelvin
8. There are different types of temperature
measurements:
1. Liquid-in-glass thermometer
2. Bimetallic thermometer
3. Resistance temperature Detector (RTD)
9. A Liquid-in-glass thermometer is a glass capillary
tube having a liquid-filled bulb present at one end.
This device is used for measuring temperature due
to its accuracy and the fact that it does not require
any other equipment except the human eye.
10. Bimetallic thermometers are made up
of bimetallic strips formed by joining two different
metals having different thermal expansion
coefficients.
Basically, bimetallic strip is a mechanical element
which can sense temperature and transform it into a
mechanical displacement.
Two basic principles of operation is to be followed in
the case of a bimetallic sensor:
11. A metal tends to undergo a volumetric dimensional change
(expansion/contraction), according to the change in
temperature.
Different metals have different co-efficient of temperatures.
The rate of volumetric change depends on this co-efficient of
temperatures .
In an industry there is always a need to measure and monitor
temperature of a particular spot, field or locality.
The industrial names given to such temperature sensors are
Temperature indicators or Gauges.
All these temperatures gauges belongs to the class of
instruments that are known as bimetallic sensors.
13. Resistance Temperature Detector is a device which is used to
determine the temperature by measuring the resistance of pure
electrical wire.
This wire is referred to as a temperature sensor. If we want to
measure temperature with high accuracy, RTD is the only one
solution in industries.
The main principle of operation of an RTD is that when the
temperature of an object increases or decreases the resistance
also increases or decreases proportionally. i.e. positive
temperature co-efficient.
Platinum , Nickel and Copper are the most commonly used
sensing elements.
15. An accurate determination of temperature is an important factor in many
industries as follows:
Food and Beverage Processing:
Measurement and control of
temperature is of utmost importance for both food and beverage
processing manufacturers. Temperature is one of the important
factors to consider during the bulk production of food items. in
the beverage industry, temperature plays a vital role in deciding the
quality of the final product.
16. Plastic Production:
Temperature plays an important role in
the plastic industry. During the manufacturing stages, for
example thermoforming, or injection molding, several
temperature ranges needs to be monitored to ensure a high
product quality.
17. Metal Processing:
Temperature measurement and analysis is
plays a key role in metal processing, as well as monitoring. If the
temperature measurement information is not correct, then it can
affect quality of the final product, as well as endanger workplace
security.
18. There are temperature sensor applications in many industries
including medical, motorsport, HVAC, agriculture, industrial,
aerospace and automotive. Here are some of the specific
temperature sensor applications which we have come across:
Motors:
There are many different aspects of motors and most of
these require temperature measurement to ensure the motor itself
does not overheat.
19. Home appliances:
Kettles, toasters, washing machines,
dishwashers and coffee machines will all contain temperature
sensors.
Computers:
Within computers there are temperature sensors to
ensure the system does not overheat
Warming Electrical Radiators:
NTC thermistors are used to
control the heat on electric radiators.