Introduction to Sensors and Transducers

Sensors and transducers play ever-expanding parts in everyday life. For example, many vehicles made in the last 10 years include sensors that make it easier for the driver to back the vehicle up without bumping into anything. These sensors detect the presence of any obstruction behind the vehicle.

Sensors aren't always used in such sophisticated applications, however. For example, humidity sensors and thermostats may trigger HVAC equipment. An example of a much simpler type of sensor is the mercury contained in a standard thermometer. That mercury expands or contracts depending upon the temperature to which it is exposed, which can be converted into a temperature reading via a scale located next to the substance. Electrical sensors may seem much more sophisticated than this, but they really aren't upon closer examination.

Another common application of sensors are light sensors. These sensors may turn on lights depending upon the ambient lighting conditions or they may turn on lights depending upon whether or not a radio field is disturbed, which is how most motion detectors work.

There are innumerable different applications for sensors. From the temperature controls on your oven, which keep your cake baking at a consistent temperature, to the sensors on your digital camera that focus in on the subject you're trying to take a picture of and adjust the lenses accordingly, sensors are found in applications simple and complex and in devices expensive and inexpensive.

What has changed a great deal about sensors over the years is their sensitivity. Today's sensors are able to detect very small changes in temperature, air pressure, humidity, electrical current and so forth. This allows for very precise manufacturing and, in industrial settings, very precise control over equipment and machinery.

One of the most important applications for sensors is found in medical equipment. Medical equipment can detect dangerous variations in heartbeats, blood pressure and so forth, allowing physicians to make accurate diagnoses and to give proper treatments, sometimes meaning the difference between life and death. The sensors utilized in medical equipment have become so sophisticated that they can even detect analytes at very small scales.


What are Sensors and how do they work?

In the very simplest terms, a sensor is an electronic device that measures of physical property, converts it to a signal and outputs that signal to a device that allows it to be read by a human being. For example, a voltmeter will detect the voltage across a line, convert that to a signal and, utilizing that signal, display either a digital or analog reading on a scale that a human being can read and understand.

In electronics, there is an ideal of a component and a reality of a component that are oftentimes not quite in line with one another. For example, an ideal sensor would only be sensitive to the property being measured, would not influence the measurement of that property itself and would not be sensitive to any other property that could influence the measurement. In practice, however, sensors are subject to interference and sensitivity is never perfect.

Other electronic components can be used to detect errors that result from sensitivity, interference from other physical properties and so forth. This allows very accurate sensors to be constructed, though there are always improvements to be made. Fortunately, electrical engineers and scientists are always coming up with new ways to improve the accuracy of sensors and the sensitivity of sensors, allowing them to get more and more accurate measurements of various physical properties.

In addition to controlling interference with the signal to increase accuracy, there are different types of devices that can be utilized as sensors. For instance, a temperature sensor can use a device called a thermistor or a thermocouple, among other choices, that provide varying degrees of accuracy. Because there are so many different options available to electrical engineers in constructing sensors, they're able to make sensors that will work under just about any condition imaginable, even in the vacuum of space and on other planets. Sensors allow us to explore our world, from the bottoms of the ocean to the furthest reaches of space, and to control our world, by simply turning our HVAC equipment on or off or knowing whether somebody has entered our property, due to a motion sensor triggering outside lighting.


What are Transducers?

A transducer is an electrical component that is defined as being able to take one type of an electrical signal and convert it into another type of electrical signal. Sensors are forms of transducers, but not all transducers are used for the purpose of building sensors.

As an example of this, a transducer might be hooked up to a photosensitive device. When the photosensitive device detects a change in light, the transducer might take that electrical signal, convert it into another electrical signal and use that signal to turn a light switch on or off. Another application would be a transducer being used to transform a signal received from a humidity sensor into a signal that can be output to a digital readout, allowing a human being to get a precise reading on the humidity in a room, outside or anywhere else that the sensor is installed.

Transducers are used in a wide variety of applications aside from sensors. They are utilized in antennas, in data equipment for computers and in just about any other imaginable application where one form of a signal has to be transformed into another form of a signal to make it useful.

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There are many different types of sensors and transducers on the market. They tend to be rather specialized in their applications. Transducers can be purchased as electrical components and installed. However, an engineer needs to have them installed to get a specific function out of a device.


Absolute Pressure Sensor ICs

Absolute pressure sensors are utilized to measure pressure levels in liquids, solids and gases. They are vital for many different applications and their use is widespread. IC versions of these are simply integrated circuits that have all of the various components required for specific type of pressure sensor. In the case of an absolute pressure sensor, the sensor uses a perfect vacuum as the standard against which it measures pressure.

These types of pressure sensors are very common and, thanks to improved technology and manufacturing techniques, are actually very inexpensive in most cases.


Accelerometer ICs

If you've ever looked at your cellular phone and used it to determine how fast you were moving, you saw an accelerometer in use. An accelerometer is a component that measures was called proper acceleration. Proper acceleration is the acceleration that you can feel and is measured relative to freefall. Whenever you hear the term g-force being used, proper acceleration is being measured.

Accelerometers can be utilized to measure the position of a device, the acceleration of a device, and so forth. They are very common types of sensors and are installed in a wide variety of different equipment, from the aforementioned smartphone to your car.


Colour Sensors

Color sensors are utilized to measure exactly what the name implies. There are many challenges to these types of sensors, such as the reflectivity of the surface on which a color is being measured influencing the measurement itself. Various technologies are utilized to overcome these challenges.

Color sensors have a wide variety of different applications. They are quite frequently used in manufacturing processes when color consistency of the products needs to be assured. They can also be utilized in very sophisticated applications. For instance, they can be utilized in various astronomy applications to measure the color of stars and other astronomical objects, which allows scientists to determine a great deal about the nature of the objects being observed.


Light Sensors

Light sensors are among the most common types of sensors in use. These are utilized to turn lights on and off, saving power by ensuring that outdoor lighting does it remain on during the day. These are, of course, used on just about every streetlight in existence, precisely for this power saving purpose.

Light sensors have some significant advantages over other methods of controlling when lights turn on or off. For example, if street lights were on timers, they might turn on near sunset and turn off near dawn. However, there are many occasions – thunderstorms, windstorms, etc. – when the light conditions outside might become very dim and when streetlights need to be turned on. Light sensors ensure that, under conditions when there isn't enough ambient light to provide safe driving, streetlights do turn on. They serve the same purpose in homes and in other locations.


Hall Effect Sensor ICs

In a Hall Effect sensor, a transducer is utilized to detect changes in a magnetic field. This is frequently used for switching, detecting current, detecting position and for many other applications. One of the advantages of a Hall Effect sensor is that it can be utilized to measure current without actually changing the current in the circuit, since it is not directly attached to the circuit.


Image Sensors

Just about everybody is likely familiar with and experienced with using image sensors. The most common application for image sensors is inside digital cameras, were a CCD image sensor detects light and converts that to an image.

Image sensors can be used in a wide variety of different applications. They can be utilized in the aforementioned digital cameras and they can be utilized to scan printed media and for many other purposes. These are sensors that are continually being improved upon, with the newest sensors on the market being capable of tremendous pixel densities, allowing them to produce very high quality images, even in inexpensive digital cameras.


Inclinometer ICs

Inclinometers are utilized in a wide variety of different applications. These measure the pitch of a slope, the tilt of a vehicle and so forth. They can be used on airplanes to measure the orientation of the vehicle to the ground, they can be utilized in cars and trucks to detect whether or not the vehicle is at risk of tipping over and they can even be utilized in devices such as smartphones, allowing the device to be used as a sort of level, as the device can detect whether or not the phone is at a tilt or is completely straight relative to the ground.


Proximity Sensor ICs

Proximity sensors are among the most important types of safety equipment in existence. These can measure whether somebody is standing underneath a garage door and prevent it from closing if someone is, they can measure electrical signals that help them detect whether or not somebody is standing close to a vehicle that is about to move and they can be used for many other purposes. Proximity sensors are useful for security equipment, safety equipment and in many other applications. They can utilize different types of sensors to get the information required to detect whether or not somebody is close to an area that needs to be protected.


Temperature Sensors

Temperature sensors are another common application of transducers. These simply take temperature data and either convert it into a form that can be read by human beings or utilize that data to turn on HVAC equipment or for another purpose. There are many different types of temperature sensors, including thermocouplers, thermistors and more. They can be chosen based on cost, the specific application to which they are to be put and based on other concerns.


Humidity Sensors

Humidity sensors are commonly used in applications where the amount of water in the air needs to be closely monitored, quite frequently for the protection of equipment. For instance, most large-scale network rooms have humidity sensors installed in them so that ventilation can be used to keep humidity at levels that is safe for the equipment and that keeps it running within proper parameters. Humidity sensors are also utilized in homes, providing a way for people to maintain a certain comfort level. In the outdoors, humidity sensors can give vital information as to whether or not it is likely to rain and other information.