What is Sensors: Definition and 152 Discussions

In the broadest definition, a sensor is a device, module, machine, or subsystem whose purpose is to detect events or changes in its environment and send the information to other electronics, frequently a computer processor. A sensor is always used with other electronics.
Sensors are used in everyday objects such as touch-sensitive elevator buttons (tactile sensor) and lamps which dim or brighten by touching the base, besides innumerable applications of which most people are never aware. With advances in micromachinery and easy-to-use microcontroller platforms, the uses of sensors have expanded beyond the traditional fields of temperature, pressure or flow measurement, for example into MARG sensors. Moreover, analog sensors such as potentiometers and force-sensing resistors are still widely used. Applications include manufacturing and machinery, airplanes and aerospace, cars, medicine, robotics and many other aspects of our day-to-day life. There are a wide range of other sensors, measuring chemical & physical properties of materials. A few examples include optical sensors for Refractive index measurement, vibrational sensors for fluid viscosity measurement and electro-chemical sensor for monitoring pH of fluids.
A sensor's sensitivity indicates how much the sensor's output changes when the input quantity being measured changes. For instance, if the mercury in a thermometer moves 1 cm when the temperature changes by 1 °C, the sensitivity is 1 cm/°C (it is basically the slope dy/dx assuming a linear characteristic). Some sensors can also affect what they measure; for instance, a room temperature thermometer inserted into a hot cup of liquid cools the liquid while the liquid heats the thermometer. Sensors are usually designed to have a small effect on what is measured; making the sensor smaller often improves this and may introduce other advantages.Technological progress allows more and more sensors to be manufactured on a microscopic scale as microsensors using MEMS technology. In most cases, a microsensor reaches a significantly faster measurement time and higher sensitivity compared with macroscopic approaches. Due to the increasing demand for rapid, affordable and reliable information in today's world, disposable sensors—low-cost and easy‐to‐use devices for short‐term monitoring or single‐shot measurements—have recently gained growing importance. Using this class of sensors, critical analytical information can be obtained by anyone, anywhere and at any time, without the need for recalibration and worrying about contamination.

View More On Wikipedia.org
  1. as919461

    How best to install a pressure sensor inside a pipe?

    Dear memebers, I have a test setup with a pipe (25 mm dia) having certain holes with a suction fan at the end of pipe. I need to check the suction pressure generated in the holes. What type of sensors can i use to install inside the pipe (above the hole in the mainstream) which doesn't disturb...
  2. PEEE

    Any online courses (like Coursera) recommended for analog electronics?

    TL;DR Summary: Are there any online analog electronics courses through recommended where I can go at my own pace? I would like something like Coursera. I am a recent graduate with a background in power electronics. I am starting to do more analog electronics which I an not really familiar...
  3. Anas Benti

    What can I add to a Taekwondo body protector scoring systeme to be more stable?

    I am developing a Taekwondo body protector scoring system using a textile piezoelectric sensor. The sensor is designed to detect mechanical force and convert it into an electrical charge. However, it is sensitive to temperature variations, leading to potential inaccuracies and instability in the...
  4. Tone L

    I Can an Aspheric Lens Narrow the FOV for Motion Detection Systems?

    I want to build a motion detection system, however I want to narrow field of view. I cannot find a Fresnel lens with a narrower FOV than 30 degrees. Was looking for something around 20 degrees. Can I use an aspheric lens to achieve this, does anyone know?
  5. benagastov

    I Photodetector Output & Refractive Index of FO Cladding/Coating

    After I finished preparing gas chamber for testing optical fiber as gas sensor, my supervisor asked me to measure the difference of refractive index from several optical fiber with different coatings. I knew there is Evanescent Field and Skin Depth effect, but what kind of mathematical formula...
  6. S

    Engineering Measuring rotational speed for Tachometer vs Oscilloscope

    Question: Why does the oscilloscope double almost the exact value of rotational speed measured by Tachometer? Rotational speed from Tachometer = 1930 [RPM] Frequency of 1 period = 64.3 [Hz] which means 3857.91 [RPM] The output waveform of hall-effect sensor is attached. Can you have any...
  7. vela

    Phyphox free cell phone app for sensors

    At the Fall SCAAPT meeting, I learned about a free cell phone app, phyphox, which allows users to collect various types of data using their phones' sensors. I downloaded it, but I haven't looked into it very much yet. I just thought I'd mention it since others might find it useful or just fun to...
  8. core7916

    Automotive Websites for getting datasheets for Ford 220HP engine sensors?

    Can anyone suggest sites for getting datasheets of ford engine 220hp sensors (sensor datasheets). Like cam sensors, crank sensor etc.
  9. L

    Engineering Adding two signals from different sensors in order to obtain a signal with very high dynamics

    hello I am working on a project concerning a measurement technique which consists of adding two signals from different sensors in order to obtain a signal with very high dynamics. and I would like you to help me because I saw your interventions concerning this system. I don't know yet if this is...
  10. L

    I Optimizing Sensor Thickness for Efficient Optical Wavelength Detection?

    When creating sensors to record images from much larger wavelengths of radiation, must the sensor be at least as deep as the wavelength, or is there a way to make it more compact?
  11. BillTre

    Volcanologists want to put sensors directly into an Underground Magma Chamber

    This Science magazine news article discusses how a magma field was accidentally drilled into and how they plan to make a more permanent magma observatory.
  12. sodoyle

    Power Over Fiber for Small Sensors

    I have a "high votage" converter with components at different voltages distributed throughout. I have some sensors that need to be powered in one location that's some distance from its power supply. I want to minimize (or eliminate) the high voltage wires routed throughout the converter. My...
  13. J

    Electronics How do sensors handle interference due to the reflected ray?

    I am unable to see how a sensor where the receiving and emitting instruments are next to one another deal with wave interference between the emitted and reflected wave.
  14. S

    How Are Materials for Infrared Sensors Selected and Developed?

    Hello. I am curious to know if anyone here has interest in talking about materials used for an infrared sensor and how to grow them. I have read about carbon nanotube forests and things like that. Apparently, to achieve the highest sensitivity to infrared light, the key is in the elements used...
  15. nomadreid

    Sensor data in Deep Learning: questions on a simple level

    First of all: I am not a programmer, I cannot read code, only have a background in pure mathematics, am looking for a very simplified summary ("for Dummies") of the way Deep Learning and similar AI routines handle sensor data. I looked at a few articles such as...
  16. R

    Find suitable SI units to work with a Vibration Sensor

    We are working on an IOT project in which we are trying to learn about different vibrations of using Wireless Vibration Sensor According to the manual, the wireless vibration sensor is giving the output while testing on CNC machine device 0.75, 0.71,0.69 whose SI units are in 'g'(which is...
  17. S

    A change in the dielectric constant changes the current or voltage?

    hi everyone! i am not into physics, but need it now,i am a programmer workin on an IOT project...so kinda need help. i want to use a capacitor to see what passed between two plates...knowing, it is the change in dielectric after certain intervals...how do i measure the change at the other...
  18. A

    How Do Biomimetic Sensors Work?

    Hi all, Ameya here from the University Of Twente Netherlands pursuing masters in electrical Engineering. Currently doing my thesis. My topic involves developing a biomimetic sensor.
  19. S

    How Many Sensors Does a Typical Rocket Have?

    Hi,does anyone know how many sensors a typical rocket have and what they are? Where can I find such a list?Senmeis
  20. S

    Effortlessly Send Data via Motion Sensors with WIFI Technology

    Does anyone know how i can send information to the web through motion sensors?
  21. R

    Interface Wireless Frequency Sensor with Arduino

    Hello, I am going to interface wireless frequency meter transmitter with Arduino but before starting regarding sensor, I need to test the signal strength of this sensor (at different distances) by interfacing it with Arduino, I have never been used such kind of sensor before so any suggestion...
  22. akaliuseheal

    Use of 4 floating current sources

    Homework Statement I have 4 resistive sensors thus I need to tie 4 floating current sources. Floating current source will give me output voltage linear to the resistance of a sensor. I know it is not the best solution but it is good enough. Image provided: Homework Equations None The Attempt...
  23. S

    Cloud cropping/plureite sensors

    I saw a video on facebook recently of some sort of devices making circles in the clouds, revealing the blue sky above. I thought at first this was fake but apparently not. Someone provided the explanation using the above terms...cloud cropping and plureite sensors, but I can no longer find the...
  24. D

    About atmospheric remote sensors

    Hi I am currently involved in atmospheric remote sensors on board a satellite which collect back-scattered and reflected solar radiation to provide atmospheric composition measurements through an algorithm based on Differential Spectroscoy. I am currently involved in studying the physical...
  25. berkeman

    Any idea what these sensors are on lightpoles in a stadium parking lot?

    I've been trying out a couple new running routes around work lately, and my run today through Levi's Stadium parking lot (yes, my work is right next to Levi's Stadium, oh joy) took me past light poles that have some kind of sensors attached to them. I wasn't able to figure out what they might...
  26. adamaero

    Engineering KVL and sensitivity of a simple circuit

    Homework Statement Homework Equations The Attempt at a Solution Note to self - simple diode concept: http://www.cs.tut.fi/kurssit/TLT-8016/Chapter3.pdf#page=5 Unsure about this KVL (above). For the last sensitivity part, equations be falling out of the sky...
  27. Hareesh Venkatraan

    Sensors for checking whether there is any dirt on the floor

    Hello guys. Is there any sensors to check if the floor is dirty.For Example, the roomba room cleaner bot uses Piezoelectric sensor to check if the floor is dirty. What other sensors can be used for this same purpose? Thank you.
  28. T

    Explore New Business Fields for Light Sensitive Sensors

    Hey :) I am currently doing a project on university in cooperation with CERN where I have to find new business fields for light sensitive sensors (CMOS) which every camera contains. The special feature is the radiation hardness. So you can use it for example for detecting x-rays or you can use...
  29. T

    Which Ultrasonic Sensor is Best for Low Cost/Long Distance Proximity Sensing?

    I am new to sensors and am looking for an ultrasonic sensor with a range up to 16-18 feet for very low costs (<$10). Most sensors I have found for this project are pricey relative to the cost I imagined. Are these type of sensors the best option if I am looking for low cost/long distance...
  30. K

    Water Level Sensors: Strange Behavior?

    HI All, Has anyone experienced strange behavior with capacitive level sensor? They fail (not detecting fluid) at certain point and after leaving them alone for couple of days start working?
  31. S

    What magnetic position sensor to choose?

    I want to record the displacement of a small magnetic ball moving sideways across the face of the sensor. I've had a close look at AMS's catalog of magnetic position sensors and I'm not sure how to choose one. If I'm working with a movement range of <5mm and want a resolution of 5-10μm, and...
  32. K

    Sensors and transducers, transmission, signal conditioning

    Homework Statement Q1. A hydraulic jack has a load piston diameter of 150 mm, and a plunger diameter of 25 mm a) Ignoring loses, calculate the force needed on the plunger to raise a load of 2500 kg b) Calculate how many stroke of the plunger will be required to raise the load 180 mm, if each...
  33. M

    Find Reliable Current Density Sensors for Aluminum Foil Treatment

    Hi all, don't know if this is the appropiated place to search. I am trying to find a supplier for a current density probe (Hall sensor or similar) to measure the current density in a tank where an aluminum foil is treated to form electrolitical capacitor. Im searching for this in Europe and USA...
  34. J

    How to determine the range of sensitivity for a camera sensor?

    I am not sure if this is the best place to ask and I will change locations if need be, but I need some guidance on how to choose a proper sensor for my project. I am currently working as part of a team on a polarimetric camera for ocean imaging. The basic premise is that images, from above the...
  35. B

    Refraction of IR "light" in CCD sensors SiO2 layer

    Dear friends I am new at this forum thank you for accepting my application first of all. My question is that I don't understand the optics/physics behind the reason why Si-based CCDs are not sensitive for IR-light (above 1000-1100 nm) if on the top of the p-type Si there is a SiO2 layer which...
  36. Irfan Nafi

    Difference between reverse bias and forward bias for a photodiode

    I'm creating a project where the motors have to be triggered by a photodiode. A light provides a steady stream of current to the photodiode and when that incident light is scattered, the motors move. But in reverse bias a photodiode needs to have a dark environment to provide 'infinite...
  37. omar-us

    TEG&Li+ batteries to power data collection sensors

    Hi all, This is Omar undergraduate electrical engineering student. I am doing my senior project on powering data collection sensors( 3- resistance temperature detectors and 1- pressure transducers) of autoclave by using thermoelectric generator!. the sensors are connected in // to a 24V common...
  38. M

    How can I connect sensors in a household without a laptop or large controller?

    Hello everyone, I am a 4th year Mechanical Engineering student and recently completed a course called Instrumentation and Measurements. We used different sensors and actuators that we connected to a : myRio controller, breadboard, computer software (LabView). My question is, how can I connect...
  39. Benighted

    How to interpret this circuit configuration? (Sensor bridge)

    So, I'm asked to demonstrate the formulas for finding out the voltage labeled here as ΔU, which I'm given in my project document: I think I would be able to make the demonstrations without any outside help, if only I knew how I'm supposed to interpret this circuit branch in the middle. Is it...
  40. G

    Potential divider to adjust volume and sensors

    Can someone explain in depth ( in simple term) how potential divider is link to adjusting volume and sensors. Please share any digram if it ia helpful for me. Thank you
  41. wukunlin

    Engineering Image Sensors: Books on CMOS & CCD Design, Manufacturing, & Quality Control

    I am looking for texts on image sensors (mainly CMOS but CCD won't hurt). More specifically: - Working principles - Design - Manufacturing process - Quality control Are there any recommendations? So far, I can only find the following but I am unsure if there are more suitable ones...
  42. rushi121

    Detect Window/Door opening closing using sensors

    How can we detect whether a home window or door is opened or closed using sensors. I know it can be done using proximity sensors and window sensors. I want to know all possible ways/sensors to detect it. I am no way related to physics so please try to answer considering that :) Thanks in advance.
  43. yousaf nasir

    What type of pressure and temperature sensors should I use?

    hello. My FYP is to observe the behavior of a valveless pulse jet by changing shape and dimensions of combustion chamber( i am keeping the volume of combustion chamber constant). i need to know what type of sensor should i use for temperature and pressure measurement. I mean temperature should...
  44. D

    How to Waterproof a Strain Gage?

    Hello all, Our project needs to implement a force (strain) gage underwater for one of our tests. Our budget is pretty tight and we can't afford a wash-down strain gage that can support the forces that we will be operating at (~500 lbs). Does anybody know a way to hermetically seal a strain...
  45. A

    Can Accelerometer, Gyrometer, and Magnetometer Data Determine Object Projection?

    Is it possible to get the projection of an object with the help of accelerometer,gyro-meter and magnetometer data?
  46. J

    Luminous emittance vs value recorded on image sensor

    Assume that I have a light bulb with luminous emittance of 160000lux (16ev), and a gray wall with luminous emittance of 300lux (7ev). I take the photo of this bulb and this background. Is there any approximate formula to estimate the gray level or RGB value of the bulb and the background in the...
  47. S

    What changes does human body exert when it enters a room ?

    I am making home automation model and I have few sensors installed to sense some changes in the environment to detect any changes. So these sensors provide me data , but I want to know what changes does Human body exerts on the environment it enters, so that I can install those sensors which...
  48. EternusVia

    Data Corruption from Sensors with Long Wires

    Hi all, Hopefully this is the right subforum. I have a question related to Arduino sensors. Q:Generally, when do you need to be worried about losing data from having long wires from your sensor to your Arduino board? Details:For example, I've been looking at two sensors. Sensor 1: MLX90614...
  49. B

    Explosion-Proof Linear Position Control Sensor: LVDT vs. Ultrasonic Comparison

    Homework Statement , [/B]I have to recommend a linear portion control sensor, that can be used in an explosive enviroment. Unsafe electrical contacts should be avoided and the case must not permit any dust or water.Homework EquationsThe Attempt at a Solution . [/B]My thoughts are either a LVDT...
  50. A

    "Black sun" effect in CMOS sensors

    Hi, I would like to understand the reason for the "Black sun" effect that occurs in CMOS cameras (very bright spots appear as dark). Thanks, ALex