Sensor

A sensor is a device that picks up and reacts to a signal or stimulus. It notices changes around it and changes them into an electrical signal that computers or other devices can understand.

Sensors are used in many everyday things. For example, touch-sensitive elevator buttons use a tactile sensor, and some lamps get brighter or dimmer when you touch their base. You can also find sensors in cars, airplanes, robots, and medical tools.

Because of better small machines and easy-to-use computer chips, sensors can now do more than just measure temperature or pressure. They can detect movement, light, and even certain chemicals.

Sensors can be very small, made using special technology that creates them on a microscopic scale. These tiny sensors can measure things quickly and very accurately. They can be used for short-time checking or one-time measurements.

Classification of measurement errors

A good sensor should be able to detect exactly what it is meant to measure. It should ignore other factors that might interfere and not change the measurement itself. Most sensors work in a simple way. Their output changes evenly with the measurement. For example, a temperature sensor might create a certain amount of electrical signal for each degree the temperature changes. To understand what the sensor is telling us, we sometimes need to adjust the numbers a little.

Sensors are not perfect, and some common problems can affect their results. Sometimes the sensor’s output can reach a maximum or minimum limit if the measurement goes beyond what it is designed to handle. Other times, the sensor might give slightly different results based on past measurements, or it might show small random changes over time. These differences can come from many places, like changes in temperature or tiny amounts of “noise” in the signal. By testing and adjusting sensors, we can often make them more accurate.

Chemical sensor

A chemical sensor is a special device that can find out what chemicals are in liquids or gases. It changes the chemicals it finds into a signal we can measure, like a light or sound. This helps us know how much of a certain chemical is there.

Chemical sensors have two main jobs. First, they find the chemicals by using special parts that stick to them. Then, they change this into a signal we can read. Some of these sensors use living materials, called biosensors, but they can also use made-up materials, such as special plastics or tiny molecules.

Main article: Biosensor

Biosensor

Main article: Biosensor

In medicine and technology, biosensors are special tools that find important substances. They use parts from living things, like cells or proteins, to work. These sensors are different because they have living material inside them. They can be used both outside and inside living things. The living part is kept safe inside the sensor by thin barriers or special materials, so it can work well.

Neuromorphic sensors

Neuromorphic sensors are special devices that mimic how nerves in our bodies work. They are made to act like real nerve cells, helping machines sense and respond to changes around them. One example is the event camera, which can quickly detect and report movement or changes in light.

MOS sensors

MOSFET sensors were created after the MOSFET was invented in the late 1950s. These sensors help us measure many things, like physical, chemical, biological, and environmental conditions.

There are many kinds of MOSFET sensors. Some are used in medical tools to detect things like DNA, blood markers, and glucose levels. Others are used in cameras and computer mice. These sensors can also monitor homes, offices, farms, traffic, weather, air quality, and temperature.