It would have been helpful to explain how exactly the internal circuit works, some people assume they use radar which is wrong. Also the output stage is important. The main competition with inductive sensors is mechanical switches and they have advantages in how they can be wired which transistor outputs do not.
Thank you for the comment. You are correct, no radar is used! Basically, these sensors use an oscillator circuit to cause a fluctuating magnetic field to be created via an inductor, which will pass a certain amount of current which is detected by the sensor circuit. When an object comes near, this magnetic field is modified, leading to a different current detected in the circuit, which leads to a switching of the sensor state.
For aircraft/aviation applications, is circuit normally closed or normally open? Please also send me a link if you have a specific video for aircraft applications. Thanks!
Thank you for your question. Sorry, we do not have any specific videos for aeronautical applications. Circuit sense (normally open or normally closed) is usually independent of the process type and dependent only on the application. Applications where a proximity switch would need to cut off a circuit when the switch point is reached would typically be in a normally closed circuit. If the switch needs to enable a circuit, that would be a normally open circuit.
Thank you for your question. Yes. As our video explained, proximity and inductive sensors are exchangeable words depending on the sensor you need. Here is a link you can learn more about these products. Pick your country and read about the different devices you can purchase and the manufacturers who make them. us.rs-online.com/view/search?keyword=inductive%20senesors Happy learning!
@@realpars Sir Can you answer me one thing If in Examination if it is asked write proximity sensor can we write inductive sensor as one of its type or inductive proximity sensor is different from normal inductive sensor?
Thank you for the explanation.. I have a doubt, if capacitive sensor can sense both metallic and non metallic objects then why we are using inductive sensor!? Please help me with this!
Inductive sensors typically have a faster response time and a higher switching frequency. They are usually more reliable and less expensive. The biggest advantage of inductive sensors is that they are insensitive to non-metallics: i.e., they are not affected by dust, coatings, etc.
I have a question is it applicable in conveyor positioning coal industry in coal power plant with coal dust all over it? will the dust affect its sensitivity ? thank you
As stated on the video, only physical damage can affect the sensor, see video time at 5:17. Dust can not do harm or destruct the sensor as it will continue operate as long as it is serviced and well mentained.
They already did one on NAMUR proximity sensors, but not sure if you are asking about NAMUR vibration sensors? ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-0hPVyFPcVAM.html
NAMUR sensors are typically used with an intrinsic safety barrier. That limits the amount of power available at the sensor and limit it's availability to store energy so it can't cause a spark hot enough to cause an explosion.
Hi there, Thank you for your question! As mentioned in our video, the sensor operates by generating an electromagnetic field. Depending on the specific manufacturer and the information provided in the sensor's datasheet, it may be possible to effectively obstruct the electromagnetic field using a non-conductive material such as a thick piece of wood or rubber. We wish you success with your experiment and hope you find valuable insights. Happy learning from RealPars!
Can this sensor be used for rotation detection? Flat smooth surface wheel is rotating without any holes or anything on it. How can I detect wheel is rotating? If this sensor cannot do it what can I use?
To use an inductive sensor with a rotating wheel, the wheel would need to use a special version of an inductive sensor, known as a Hall Effect sensor. This sensor looks like most other capacitive or indictive proximity sensors, but specifically can detect the presence of a magnetic field. You would need to have magnetic material mounted on the surface or embedded in the rotating disk or shaft at several places on the circumference. Using a proximity switch with a fast response time, you can count the number of magnetic pulses as the item rotates. The rate of the pulses is proportional to the speed of the wheel. The only other way to determine rotation is to have a device attached to the shaft with a pickup sensor. These are also magnetorestrictive or hall effect sensors, but rather than embed something in the wheel itself, a disk is slipped over and affixed to the shaft to provide the rotating magnetic targets (e.g., www.electro-sensors.com/products/shaft-speed-sensors/series-18).
It may vary slightly, but in my experience, painted steel should give the same response at the same distance as unpainted steel. As with any proximity switch, test the switch with a sample of the material you are trying to sense. Not all steel reacts the same to the same switch, since the composition of steel varies with type.
The short answer to your question is "yes". Proximity sensors are a class of sensors used to detect the proximity of an object to the sensor. In this video, we talk about inductive proximity sensors. There are other types of proximity sensors, such as capacitance and Hall Effect proximity sensors.
I'm facing a little problem at my production plant,My Toaster plant is trip every 15 mints where inductive sensor is place near vibratory motor conveyor,tell me the solution how to fix this and my production does not stop, Thanks
Hello and thanks for your video! May I know your opinion if the sensor can be damaged by the sensing object without touching the sensor? I am sure that is not possible but I have to prove it to my boss!
I do not believe a proximity sensor can be damaged by an object without the object physically touching the sensor. Dust or grime buildup can affect the sensor and could possibly cause it to malfunction (sense an object when one is not present), but this does not damage the sensor. The only damage I have seen with proximity sensors is damaged caused to the internal circuits when they are used to switch too high of a load (like a motor).
The best way is to refer to the datasheet provided by the manufacturer. Even after working with over 1000 of these devices over the past 30 years, I still find it better to refer to the datasheets as opposed to trying to guess as to how a particular device works, its sensing range, wiring, and action (NO/NC).
Again; thanks a million times for your amazingly explained videos! Yet, I've a short question please, May i get the link to the Tester you used @ 06:05 i do highly appreciate your reply
The tester used in the video may not be available any longer. An alternate can be found here: www.pepperl-fuchs.com/global/en/classid_146.htm?view=productdetails&prodid=13178. There are others you can find by searching for "proximity sensor tester" with your favorite web browser.
Cool video all my questions answered. The machines I work on rotate and I want to add a feedback to know when the object being rotaed has stopped or jammed
Flush-style sensors actually have a shield that restricts the magnetic field so that it only radiates out of the face of the sensor. ... Non-flush, or unshielded sensors, do not have the shield around the end of the sensor so the field can radiate from the face to the sides of the sensor in a larger pattern.
first thank you. could you please give me some lessons that how the normally-open would be closed electrically? I mean in case of electromagnetic what happens exactly?
The only way to do so is to use a small magnet and test it on the metal in question. If you know what metal it is, you can search for its magnetic properties on the internet. But be careful; materials under a single name may vary in composition and magnetic properties. Best way to use a magnet to find out.
No. For AC sensor, there will be no change in operation. A magnetic field is produced and the sensor will continue to act as an inductive sensor. For a DC sensor, the device will cease to work if the leads are reversed (actually, there are 3 wires for a DC inductive sensor). DC inductive sensors are solid-state devices that require a specific polarity to function.
Great question! NO/NC and NPN/PNP are two different, but related concepts. Normally open contacts do not pass current when they are in their "normal" or at-rest state. The same is true for an NPN transistor when its base is held at 0V. However, I can arrange two NPN transistors to form an NPN inverter, in which case it will act as a normally closed arrangement. It is best to think of transistors as logic elements that drive the final state of the device. Always refer to the manufacturer's datasheet for the device to make sure you understand the behavior of the device. Here is a website that sells proximity switches: www.mcmaster.com/proximity-switches/dc-metallic-object-proximity-switches-9/. If you look through the list, you can see that there are NPN and PNP devices available in both normally open and normally closed switch designs. I know, it is a little confusing, but remember, NO vs. NC and NPN vs. PNP are two different design decisions that need to be made.
Variable reluctance sensors are pretty much the same. Hall effect sensors are also similar and have better responses at lower speeds. The key is to match the response time of the sensor to the application it is being installed in. The switch needs to have a short enough switching frequency to be able to return to the "zero" state between pulses at maximum speed
Only if you can trace the wiring. In PNP, the black wire will be connected to the positive or signal terminal of the PLC input or positive side of the device. For NPN, the black wire is connected to the negative side of the PLC input or device. If you can't see the wires, the wire colors are "lost" when connected in a marshaling panel, or you can't trace them back at all, then read the model number off of the sensor and look up the specifications in the manufacturer's documentation.
You are wrong. NPN - Which gives output negative. PNP - Which gives output positive. Depending upon Application we use that . Ex For sinking we use PNP For sourcing we use NPN