SENSORS

WHAT IS A SENSOR?
A sensor is a transducer whose purpose is to sense or detect events or changes in quantities and provides a corresponding output, generally as an electrical or optical signal.

RADAR GUN

SOME RULES:

• should be sensitive to the measured property only
• should be insensitive to any other property likely to be encountered in its application
• Does not influence the measured property

Faraday cup

WHAT IS SENSITIVITY?
The sensitivity is then defined as the ratio between output signal and measured property.

For example, if a sensor measures temperature and has a voltage output, the sensitivity is a constant with the unit [V/K]

Geophone

WHAT ARE ITS TYPES?

Automotive         -  Radar gun, Speedometer, etc.
Acoustic              - Microphone, geophone, etc.

Galvanometer

Electric/Electronics/Chemical Fields       - Smoke Detector,            Galvanometer, Faraday Cup, etc.

Environment       - SNOTEL, Tide gauge, etc.
Others                 - LIDAR, Tachometer,PMT, Barograph, Pyrometer                               etc.

WHAT IS RESOLUTION?
The resolution of a sensor is the smallest change it can detect in the quantity that it is measuring.



EXAMPLE: A thermocouple converts temperature to an output voltage.





APPLICATIONS: Applications include manufacturing and machinery, airplanes and aerospace, cars, medicine and robotics.

J C Bose - A Pioneer

Acharya Sir Jagadish Chandra Bose was a Bengali polymath, physicist, biologist, botanist, archaeologist, as well as an early writer of science fiction. He made very significant contributions to plant science.  He used his own invention, the crescograph, to measure plant response to various stimuli, and thereby scientifically proved that plants have life.

He pioneered the investigation of radio and microwave optics,  IEEE named him one of the fathers of radio science. He was the first to use semiconductor junctions to detect radio signals. However, he did not wanted to take commercial benefit from this invention, and made his inventions public in order to allow others to further develop his research. As a result it took 100 years for the world to rightly credit him with invention of first wireless detection device.  Bose work in radio microwave optics was not related to radio communication but his research may have been used in radio inventions by other inventors.


One of the greatest Indian scientist who believed technology was never meant to be patented but to be used by one and all. As a pioneer, J.C. Bose has remained an inspiration to thousands of Indian students aspiring to a career in science.

Solenoid Valve

What is solenoid valve?
A solenoid valve is an electro-mechanically operated valve. The valve is controlled by an electric current through a solenoid.
or
A solenoid is electrically operated valve. It consists of solenoid coil in which magnetic plunger moves. This plunger is connected to the plug and tends to open or close the valve.

(Fig. shows Water solenoid valve)

How does it works?
(In diagram Explanation)

What are its types?
There are two types of solenoid valves:
1. Normally Open
2. Normally closed

Where it is used?
It is used for safety purpose in different electric work
Solenoid valves are also used in fluid power pneumatic and hydraulic systems, to control cylinders, fluid power motors or larger industrial valves.

Birth of an era of Auto-mobile

The world we live in today has witnessed a large number of transport options. With two wheelers and Four wheelers visible in every nook and corners. But 100 years ago it wasn't the case, owning a car in those days, was like owning a private jet these days. It was too costly for common man. And that's when Henry Ford decided to make cheaper cars available for everyone it was like ratan tata wanting to make NANO just hundred years back.

Ford's idea to produce an affordable car was through use of the assembly line that increased efficiency and decreased cost. Before assembly lines, cars were individually designed by number of skilled mens - a slow and expensive procedure. With the introduction of assembly line ,Instead of workers going to the car, the car came to the worker who performed the same task of assembly over and over again. With this, Ford was able to reduce the assembly time of a Model T from twelve and a half hours to less than six hours.

On December 1, 1913, Henry Ford installs the first moving assembly line for the mass production of an entire automobile. And thus began an era of automobile for everyone.