Sensors: Everything you Need to Know | Ashraf Madhoun | Skillshare

Sensors: Everything you Need to Know

Ashraf Madhoun, An Engineer with +10 Year Experience

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25 Lessons (1h 23m)
    • 1. 1 Introduction

      1:11
    • 2. 3 Temperature Sensor Thermocouple

      7:43
    • 3. 4 Temperature Sensor Resistance Type Sensor

      6:16
    • 4. 5 Temp Liquid expansion and Vapour Pressure Sensors

      1:56
    • 5. 6 Temp Bimetallic Type

      2:57
    • 6. 7 Temp Glass Thermometer

      3:41
    • 7. 8 Pressure Sensors

      1:15
    • 8. 9 Pressure Bourdon Tube

      3:13
    • 9. 10 Pressure Piston Type

      3:13
    • 10. 11 Pressure Capsulse and Bellows

      2:20
    • 11. 12 Pressure Diaphragms

      1:53
    • 12. 13 Pressure Electrical Intro

      1:05
    • 13. 14 Pressure Electrical Piezo Electric Types

      2:12
    • 14. 14 Pressure Electrical Strain Gauge

      3:05
    • 15. 15 Speed Sensors Optical Types

      3:13
    • 16. 16 Speed Sensors Magnatic Pick Ups and Tachometers

      3:00
    • 17. 17 Flow Meters Positive Displacment Types Intro

      3:18
    • 18. 18 Flow Meters Inferential Type Meters

      3:54
    • 19. 19 Flow Meters Variable Area Types

      4:27
    • 20. 20 Flow Meters Variable Area Types

      4:12
    • 21. 21 Force Sensors

      4:54
    • 22. 22 Position Sensors Resistive Type

      3:01
    • 23. 23 Position Sensors Optical Type

      5:46
    • 24. 24 Position Sensors Inductive Type

      3:25
    • 25. 25 Depth Gauges

      1:39

About This Class

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>>> Learn Everything there is to know about Sensors,how they work and how to interface them and why we need them in our life <<<

Welcome to this course. More Than 40 Sensors are Explained in Full Details, See List Below

Learn Sensors Interfacing and Working Principle Today

This Course will teach you how Sensors Work, What they measure, how they measure it and what is the actual working principle for sensors.

Different Type of Sensors are covered in this Course:

- Temperature Sensors

- Pressure Sensors

- Force Sensors

- Position Sensors

- Speed Sensors

- Depth Sensors

- Flow Sensors

You will know Why Sensors have Standard output Range and which sensors to buy, everything is explained in full details.

A List of Sensors and Sub Categories Covered in this Course:

  • TEMPERATURE TRANSDUCERS

  1. THERMOCOUPLES

  2. RESISTANCE TYPE SENSORS

  3. LIQUID EXPANSION and VAPOUR PRESSURE SENSORS

  4. BIMETALLIC TYPES

  5. GLASS THERMOMETER

  • Mechanical PRESSURE TRANSDUCERS

  1. BOURDON TUBE

  2. PISTON TYPE

  3. CAPSULES AND BELLOWS

  4. DIAPHRAGMS

  • ELECTRICAL PRESSURE TRANSDUCERS

  1. Strain Gauge types.

  2. Piezo electric types.

  3. Other electric effects.

  • SPEED TRANSDUCERS

  1. OPTICAL TYPES

  2. MAGNETIC PICK UPS

  3. TACHOMETERS

  • FLOW METERS

1. POSITIVE DISPLACEMENT TYPES

Lobe type or meshing rotor.

2. INFERENTIAL TYPES

Turbine rotor types

Rotating vane types

3. VARIABLE AREA TYPES

Float type (Rotameter)

Tapered plug type.

4. Fluted spiral gear.

5. DIFFERENTIAL PRESSURE FLOW METERS

  1. ORIFICE METERS.

  2. VENTURI METERS

  3. NOZZLE METERS

  • FORCE SENSORS

  1. Mechanical types.

  2. Hydraulic types.

  3. Electrical strain gauge types.

  • POSITION SENSORS

  1. RESTIVE

  2. OPTICAL

  3. Linear

  4. Rotary

  5. INDUCTIVE

  • DEPTH GAUGES.

  1. Ultrasonic Sensor

  2. Pressure based Depth Gauge

  • STRAIN GAUGES

After this course, you will be able to recognize any Sensor and know the actual working principle behind the plastic boxing that most sensors have. Everything is explained in details.

Transcripts

1. 1 Introduction: hello and will come to this new course in which we will talk about sensors on how to interface them. They're working principle on everything you need to know about them. We will cover the front type sensors four sensors Andi flow meters. In addition to other type of sensors like temperature sensors and speed sensors. Each of these categories will take more than one example. We will discuss how it works on how to connect it. Probably what are the types available in the market? It's working principle on all of the information that you need to know before start using these sensors in your industrial life. Andi in your electron, ICS or microcontroller on life. I'm sure that you will enjoy this course content. Andi, I'm sure that will add a lot off knowledge to Thanks for watching this introduction. See you inside. 2. 3 Temperature Sensor Thermocouple: temperature transducers. Today we'll start with temperature sensing. As you know, temperature is one of the most commonly sense signals in the world. We use a lot off devices to measure temperature. We'll start by the most common one that's used in industry and in electron ICS on banker controller projects, which is fair, more couple. The basic principle off firm a couple is when two wires with this seminar electrical probabilities are joined at both ends on one junction is made hot on the other is made cold . A small electric current is produced proportional to the difference in the temperature. Now, if you want toe, make it more clear than introduction or the definition of thermal couple and how it works. Let's look at this Symbian design. As you can see, this design in the middle of screen is for thermal cover. This is the first wear on. This is the second wave. Now, as you can see, these two wires are connected together. Two points. This is the first point on. This is the second point. Now this point is called her junction because it absorbs heat. This is the point that we bought in the place we want to measure the temperature as you're dimension thes two wires are made off this similar electrical probabilities, so the material in both of these is different. This connection connecting them at both of these points will cause a small electric current toe bus from one point to the other. When he is here, it will affect that small electric current that passes through these wires through these wires. Andi affecting these or this small electric current will be indicated via a device like this device. It's called a meter, and it's you. It usually has a set point toe. Little mind, the temperature that we want this device to be activated when it's reached. No, this is very simple. Two wires connected at both ends when it's called hurt because it's hot here it will take the heat that you want to measure on. The others called a cold point because it's connected to a meter that will take the electric current that passes through these wires because of feet. Andi, turn this into a reading here, this meters. Visibly, CeBIT discovered this effect. It's true, no matter how the ends are joined. So the cold and maybe joined at a sensitive medieval meter. The whole chunk, the junction formed the sense or and so this will be the sensor end that will take the heat . This can be assembled, Millie Volt meter. Well, a sophisticated device that takes the change in the Koran, which is very small. Amplify it until it in tow temperature reading using this symbol visibly. Now this picture shows a typical industrial bob with a flexible extension on standard blood . Usually you did see one of these. If you did visit ah factory or a place where they have thermal couples or temperature sensors, this end is pleased in the device. This will take the heat and with measuring these crops has two wires on these two wires are connected here. This club is inserted into a device like this one in order to measure the temperature or it can be connected toe a processor or amount of device bigger showed that heat is absorbed at the end and is ejected at no cold. And chief thumbs ensured that part off. The electric magnetic force is due to the temperature gradient in the wires as well as the temperature difference between the junction most thermal couples. Metals produced a relationship between the two temperature on the electric magnetic force. This relationship is represented by this equation. You don't need to understand this equation. You just need to understand the thermal Kable has two wires off this similar material that you can use to measures temperature. As you can see, this simple question is used to represent the relationship between the electric magnetic force on the temperature Alfond beater. These two signs Peter and Alpha are constants for the time off Thermal. Coupled, the relationship is nearly linear over the operating range, the actual characteristic unsuitable. Operating from Bashar depends a bone damage tells used in the wires. So it depends on the type of metal that we used to create these two. While that are connected together, the various types are designated in international and national standers. Typical leaner operating ranges are showing for standard types, but it's important that thermal couples are standards so that the same electric magnetic force will always present the same temperature as you can see in this table, we have the time off thermal couples. The two most common types are the J type on the K type. The J type comes a template charge between zero and 800 cities yous that Kate I can measure him. The charges between zero on 1200 cities is there is other types D E R. B on depending on your needs if you want to measure Called him, which are unity was died e. On. As you can see, this stable explains it all. That's it for the fares. Type off sensors used to measure temperature, which is fair. Maca bill the wires off the similar electrical probabilities connected together at both ends when it's called Hope because it absorbs he. The Arthur is called Cold Junction because it's connected toe a multi meter or a device that tells the change in current due to heat, you are reading I don millet balls or in sleaziness. That's it for the thermal problem. If you have any questions, please ask in the few unable 3. 4 Temperature Sensor Resistance Type Sensor: Hello again. Now let's talk about the second time off Temperature sensors. It's called resistance type sensor on from its name. It depends on their resistance. These work on the principle that the electrical resistance off a conductor change with temperature. If Afghanistan voltage is applied to the conductor, then the current flowing through it will change with temperature. The resistive ity off the conductor change with temperature. This usually means that resistance gets bigger as the conductor gets hotter. The following law relates the resistance on temperature. As you can see, these are the two laws are the final resistance equals the initial resistance on and open parentheses. One glass. These two constants Alfa is the temperature covert coefficient offer assistance. Tzeitel is the resistance at zero Celsius. Sometimes the equation is given as this r equals R zero one, as you can see. Plus, also Beatle on this is the angle. These are all constants used toe. Better explain the relationship. A basic temperature sensor is made by winding Athen resistance. Why are in tow a small since or head? As you can see in this about right image, this is the sensory head on. This is the thin resistance way off. That's what winding around a small sense or heads on. This is the sensor head, as you can see the resistance off the way our then represents the temperature. This has on advantage over a thermal couple in that it is unaffected by the temperature off the gauge. And the main type of fire used is Blatty new. The sensors are usually manufactured tohave resistance off 100 orme. At zero cities years on, the value off alpha is zero, going 003 A typical operating range is minus 200 to 400 seizures, a special time for assistance. And so it's called 1/3 Mr. I'm sure that you heard about it. They are made from a small bees off semiconductor material. That material is special because the resistance changes alert for a small change in temperature. Andi so can be made into a small sense, or and it cost less than that anymore. Where so the resistance type is basically how you are at a sense of head, just like in this image. Andi, As you can see, it's winding around the sensor head on. The two wires are connected to the gauge head and indicator that change in resistance is converted into a change in temperature. On is injured here using this this gauge head, it can be made off platinum. All it can be made off a semiconductor material. Semiconductor material would be a way much cheaper than platinum, but again, it doesn't measure the same temperature range. The platinum measures around minus 200 Toe Blast 400. See Liza's. This equation shows that the temperature range is limited for these. For Mr they are only used for a typical range off minus 20 to 120 degrees. Liza's that we are talking here about the semiconductor a time fairness stuff, and they are commonly used in small handheld fair Mr or Thermal meters for everyday use. The relationship between resistance and temperature is off the fall r equals a You what exponential be? They are divided by ah fi. Okay, No, As you can see, this is how the same therm a stor looks like It's a sensor head, just like the other one, Onda seed off platinum. It's made off a semiconductor material that wires are also connected toe the gauge head to display the temperature and the Schiff Discover is used to protect the device. Now again toe some of those things. We have a resistance types in sort. It's manly. Used to measure our small temperatures. There's two types of it. One made Platini, um, that measures temperature between minus 204 100. It costs are lost on the other type is made of a semiconductor material on that measures Tim the Charles between minus 20 on 120 plus silly zias. Sure for sure. This one measures ah smaller range where it comes temperature. But it costs are way, much less so. It's suitable for, ah, handheld devices. Oh, handheld thermometers. That's it for the second time, which is the resistance type sensor. Thanks for watching. If you have any questions, please ask that you aren't able 4. 5 Temp Liquid expansion and Vapour Pressure Sensors: liquid expansion and vapor pressure sensors. These are fellow meters felled with either liquid, such as mercury or on evaporating fluids such as used refrigerators. In both cases, the inside of the sense or head on the connecting toe are completely fall. As you can see, this is the sense or head, and this image on this is the connecting tool. This is the ah since or gauge or head that will show the readings for the brush up all the temperature, analyze intimate. The charge at the sensory head produces expansion or evaporating off the liquid so the sensor becomes pressurized. The pressure is related to the temperature on it may be indicated on a symbol pressure gauge. As you can see here, this is one of the simplest sense or available out there again. It depends on the president's off liquid or fable pressure evaporating fluid here in the sense or head on the connecting tube. Once there is heat here, it will expand the fluid here, and it will start pressurizing the, um, gauge heads Which internal show a reading for pressure. Autumn richer since Thies, too, have a relationship. Andi, that's it for the liquid expansion and vapor pressure sensor for measuring temperature. Thanks for watching this. Quick. Listen. See you next 5. 6 Temp Bimetallic Type: by metallic types. It is a well known principle that if two metals are originally joined together as a two layer stride and heated, the difference in the expansion rate causes the strip to bend. This is a very sill bill and easy to understand concept. Now let me draw something for you. Let's say that this is the fare Smith on. This is the second Bittle. If they are joined together at both ends here on two years on, let's say that each of them each of these tools, stripe or layers are from different materials on if we applied heat at this area, this means that one of these two layers will expand more than the other, which will cause it toe go here. Since the expansion isn't in the same rate, this will cause this stripe all this layer to bend, as you can see here. But if they both expand at the same rate, they would remain leaner. Since there are two different materials, they will expand differently, which will cause one off these two layers to bend on. The spending can be taken and the industrial time that stripe is twisted in tow. A long think oil, as you can see here. Inside the tube, one end is fixed at the bottom, off the tube. On the other, tales on moves a buoyant are on the day. So here is one end at the end of the tube for the two layers on the other end here, which will be used the bending because it to move so it will move the point of here. The outward appearance is very similar to the pressure type. They can be made toe operate, limit switches and it off alarms or act as a thermostat. And on boilers, they are very common. That's it. This is by metallic on the name explains itself by metallic, which means to Mittal's. So again, this is, Ah, one types off sensors that use to metals or two layer off different metals. When they are exposed to heat, they expand differently, which caused them to bend. And we can read the spending on about, like this one. That's it for this lesson. If you have any questions regarding the bi metallic type, please ask in the Q and A board 6. 7 Temp Glass Thermometer: glass fell moment, the ordinary last. Their motor is also a complete system. Again, the bulb is the sensor about McCullum off liquid on the scale. On the glass is the processor and indicated So if you want to name since, or a complete system must has what we call a sensor or import a processor on an indicator or output, the sense will here is being How does it go? See? Is the about on the column off liquids on the scale. Off the glass are the processor, which is the second element. The scale is basically the indicator when it's combined with the processor. Now let's take a look at this system. He comes here on here, we have mercury, and we have a scale. Once he's applied here, military, which is the processor start moving Onda scale, which, when it reaches a point at matches that temperature oblige it will stop on. We can take the readings that directly. That's why we call it Complete system. Mercury is used for hot temperatures on colored alcohol for cold temperature. The problem with the glass their moment are, is that they are brittle, so it's really easy to break them. Another problem is that mercury solidify at minus 40. Seles use the grease. It is yours, which make it really difficult. Difficult to use it in cold timber. Charles Alcohol Boys at around 120 degrees Syriza's with Smith, which make it also hard to use. Ah, glass thermometers made for made with ah Carol alcohol for hot temperatures. Accurate manufacturer is needed on this makes accurate one expensive, so it's really expensive to manufacture such sense. ALS. It's easy for people to mistake reading them because when you bring, one will have a lot off points. So it's really easy toe miss a degree or two when you read it. You can try this yourself and you'll notice the's problems. Glass thermometers are not used much now in industry, but if they are used, they are usually protected by a shield from accidental breakage. In order to measure that in Britain off something inside the bite, they are placed in a thermometer pocket to protect them because they are not strictly used for industrial purposes because they cost a lot and they can't stand too much fetal toe ah called environments. That's it for the glass thermometer next, we will talk about pressure transit users. We already talked about five different temperature sensors on how they work. If you have any questions regarding anything these ask in the Q and a bald, I'll be more than happy to help. Thanks for watching this lesson. This is educational engineering team. 7. 8 Pressure Sensors: Hello and will come to this annual Asan in which we will talk about pressure transducers. In this section, you will get introduced toe more than four types off pressure transducers how they work on how you can use them. Pressure sensors either convert the brush are into mechanical movement or into an electrical output, depending on your needs or your choice. Complete gauges not only since the brush are but indicated them on adul or scale, just like what we saw in the temperature section. Mechanical movement is produced with the following elements. Burton Tube spring on pistol billows and capsules on their farms. Thes are four types. Next lesson. We'll start with burden to It's one of the most famous type off mechanical. Ah, pressure transducers So state owned. Thanks for rushing this quick intro. This is educational engineering team. 8. 9 Pressure Bourdon Tube: Baird into the burden tube is ah, hollow tube with an elliptical cross section. When a pressure difference exists between the inside and outside, the tube tends to straighten out on the end moves. The movement is usually coupled toe a needle on other l to make a complete gauge. Let's take a look at what we just said. As you can see, this is ah, hello to in this picture. It has an elliptical cross section just like this one. Now, when pressure is applied here on, there is a difference between Russia out here and pressure inside the tool the two tends to bend so that it can, let's say, equalize the Russia. So once that hope tends to straighten on start spending, it caused a movement, and it will start moving that way when it moves. That way, there is Ellen connected to it on that link is also connected toe this years combination. Once that link is ob, the deal will move with it on. It will cause this point or to move. Now, here we have a scale. When this point are moves on that scale, it will show a reading. As you can see it has readings here and that reading in the case that Russia are obliged here again, it's really symbol we have, ah ha little with pressure inside it on. We have trash are obliged here. When there is a difference between a difference between this pressure on this pressure, this tube will start moving. Um, there it's called Straighten Out on. Once it's more it moves up, it will move. The link with it on the lingual caused this gear combination to move, which in turn will cause the point or to move on that scale, and that scared will show us a reading just like this one for the pressure. It can also be connected to a secondary device, such as on air nozzle to control air pressure or to a suitable transit user to converse it into an electric signal. This type can be used for measuring pressure difference. That's it for the burden tube again from its name. It depends on a tube that takes pressure. Then Benz, or straighten out, which intends move the point, are enough on a scale to indicate the pressure applied. Next, we'll talk about based on type. Thanks for watching this lesson. If you have any questions, please ask in the Q and A board 9. 10 Pressure Piston Type: Peston type. The pressure acts directly on the Peston on compresses the spring. Now let's first talk about this image right here. Here we have a spring as even See inside the best on on here is the best on head now pressure comes from here. From this point on, start acting on the best ahead. I'd move it aboard Now we move it up world It will cause it toe start moving up, but wouldn't move all the way because there is a spring here that forces the Preston head to move down again. The pressure acts directly on the best own aunt compresses the spring. The position often based on is directly related to the pressure. So the best in position has direct relationship with the pressure I window in the outer case allows the pressure. Toby indicated we can, uh to you a transparent window with values here. Once the pistol head stops moving, we found See, where is that? Crystal had exactly lies. So I'm doing the outer case allows the pressure to be indicated this time is usually used in hydraulic where babbles Tito the stand choke vibration on southern pressure changes is needed. Shockproof gauges. As you can see, it can understand anything because it's purely mechanical on. It's sealed. So again, how it works. It moves. The brush removes the based on head, which in turn moves that spring. Once the there's balance between the spring, let's say power on the pressure applied. The best ahead will stop moving on. We can read this from Ah, a window placed here outside the gauge to indicate where, exactly or how much pressure is applied. Exactly. The best on movement may be connected to a secondary device to convert movement into an electrical signal. It's very easy and very straightforward. If you didn't understand it, you can ask him about you and a board. Andi. I can't explain it in more details. But for now, what you need to know to know is that there is a spring that moves the based on down on the pressure that moves the piston up on when the thes two forces are equal, the best on head can be used toe. Take a reading from owned outside the gauge, which will intel indicates the pressure. Thanks for watching this lesson. Next, we'll talk about capsules on billows. That's it for this lesson. This is educational engineering team 10. 11 Pressure Capsulse and Bellows: capsules on billows I belong is made off several capsules. As you can see these, um, the billows on capsules. This is called Abalo. Each of these seven. If the items is called a capsule, these are whole off Latin structure made from thin metal blade. When pressurised, the billows expand on produce mechanical movement. It's very easy and very straight for old pressure comes from here. It pressurize, or it gets inside these capsules on. Since they are made from whole off Latin structure, they start expanding depending on how much pressure there is here. This will cause the's capsules or pillows to move up world. If the below is encapsulated inside an outer container, then the movement is proportional to the difference between temperatures are on the inside and outside bills and single capsules are used in money instrument. They are very useful from ensuring small precious. For sure, these type off off devices off sensors cannot be used to measure high pressure because they're made from thin metal plate again, this movement can be turned into mechanical movement on can be taken as a reading on adult so that it will be easy for anyone to read how much pressure is there. But again, these are only for small pressures. You cannot use them toe measure, high pressure or in high pressure situation because they will explode or they won't be efficient. Thanks for watching this lesson next week book about their from which is the last element in the pressure. Mechanical transducers or sensors. Thanks for watching this is educational engineering team. 11. 12 Pressure Diaphragms: now this is the last element in our plush Are mechanical transit yourselves. This is called their farms. This there from as you can see here, it has a very similar concept toe the capsules on billows. So they are similar in principle to the capsules. But the there from is usually very thin. As you can see, this layer is called the there from the right in the bottom right side of the slide. Andi, it perhaps made from us that they're flown expands when very small pressure is applied. From this point, As you can see, this thing down here is called the case. The movement is transmitted to appoint are on adult through a fine mechanical linkage. As I mentioned earlier, you can take this movement, aunt Using crowbar configuration, you can turn it toe readings on other as you can see here. That's it. This is the left arm. Mainly you need to know that it's used for low pressure. It's made of rubber. Most mostly, Andi. It expand slightly when small pressure is applied here. Andi, it would move the point are on a scale. That's it for this there from which is the last element in our flush are mechanical transducers. Next we'll talk about electrical pressure transducers. Thanks for watching this lesson. If you have any question about any element of this section, please ask in the human able, I'll be more than happy to help. Thanks. This is educational engineering team. 12. 13 Pressure Electrical Intro: electrical pressure transducers. There are various ways of converting the mechanical movement off the proceeding types into an electrical signal. The following are types that directly produce on electrical signal. The 1st 1 is strain gauge type. The 2nd 1 is bezel. Electric time. On the third is other electric effects. Thes three types tens pressure in tow. Electrical signal directly on. We are going to discuss them in this section. We'll start with three. Engage in the next lesson. Aunt. I'm sure that you will enjoy this very important section course. String Gage is one of the mostly used elements Industri nowadays. Thanks for watching this quick intro for this section. See you next. This is educational engineering team. 13. 14 Pressure Electrical Piezo Electric Types: bees are electric types. The element used here is a piece off crystal IQ orkest crystalline material that produces on electric charge on its surface when it is mechanical stressed. As you can see in this image, when this surface has this material, this type of material crystalline material, once there is pressure on this surface, it will increase or decrease the charge again. It's made of Arby's off really crystal crystalline material that produces an electrical charge When it service. When it is mechanical, he stressed, the electric charge may be converted into voltage. Just like in this design, we take two wires from here and here on DWI. Send them toe voltage gauge that will take that change in electric charge on disability it as a change in voltage. So the pressure here was converted to electrical signal in voltage. The principle is used in the pickup crystal off a record player in microphones on even to generate a spark in a gas ignition. When placed inside a pressure transducer that brush our is converted into an electrical signal. And if you did observe this image, you can see that once it's stressed one. Once it's pressurized, it will change on small electric charge added, will move the point on that scale. This is a Jiff image to explain it. So I hope that you got the idea again. This is a special type of material piece off a crystalline material that produces an electrical charge on the surface. When it's mechanically stressed, that's it for this lesson. Next, we will talk about speed transit users. If you have any question about anything, these ask in the Q and able. Thanks for watching this is educational engineering team. 14. 14 Pressure Electrical Strain Gauge: strain gauge types. The principal off electric strain gauge our cover in a later section, sitting gauges that would be covered in more details. Strain gauges are small elements that are fixed toe a surface that is strange. The change in length off the element produces changes in the electrical resistance. As you can see, usually special applies here. This is the thing is it will be forced, or it will. It will face pressure on this is the cable that we will take too much of a change in little stunts on turn it into a reading. This is processed unconverted into a voltage. A typical pressure transducer old contain a metal there from which bends under pressure now to make it Modica years. Imagine this as a surface. Let's say that this surface has a way off glued to it, just like in BCB design. On here we have thes two wires. Now let's say that these two wires, when we mention of the resistance between them, they give us 100 home. Now, when this surface is pressurized, it will bend a little with bending. It will cause the's fires that are glued to the surface to expand, which means that the resistance will increase and it will become, let's say, 105 or the change in resistance can be taken unturned toe voltage. And this is mainly how strain gauges works. We will talk about this in more details in a letter section, but for now you need to understand this. It's very simple verse straight for old assembly. Ah, small element that are faced toe a surface that's strange. When it does strain, it will cause the wire or that element to expand, which will increase the resistance on we can tell this increase in resistance toe vaulters using home low arms low. Ah, that's it for this lesson. I hope that you enjoyed the explanation if you didn't understand it. It's okay. We are going to explain the man working principle for electric strain gauge in a later section. But that's it for now. This is the industrial look for strain gauge. Thanks for watching this less on. See you next 15. 15 Speed Sensors Optical Types: hello and will come to this annual a stone in which I'm going to cover our speed transducers. Speed transit users are widely used for measuring the outputs, its speed off rotating object. There are many types using different principles on most off them, produced on electrical out. We will start with optical types. These used a light beam on a right, sensed if cell. The beam is either reflected or interrupted so that pulses are produced for each revolution . The buses are then counted over a fixed time on the speed obtained, as you can see in this image. At the right, there is a light source in the right and the left on a photo sense to receive our on in the right. Now this light source sends light. Undersea evils receive it. He and we have, as you can see, a shaft on and that sharp there's a rotating body on it. This shaft has a hold. Each one revolution this horn will receive will arrive to this location, causing the beam Togo from the light to the receiver from the sensor or the cinder to the receiver, which will count as about then it will keep moving again again, again again, out until it reaches this point, which will again cause it toe. Allow the light from the source to the receiver and we count another. But so this is the first pulse. Now again, this is the second balls on so on will keep adding buses on By counting the number of policies over a period of time, we can measure the speed of this shaft. This is basically what the optical time does. Electrical processing is required two. Time the bosses until the result into an analog or digital signal. Again, this optical dark time depends on a cinder onda receiver. Now, instead of the whole their car, there could be ah reflected surface that will reflect the beam. It will does the very same thing. Each time they reflected surface is reached. It will generate a balls by counting the number of policies over a fixed of time. We can obtain the speed. This is how the optical type works. Next we will discuss the magnetic type. Thanks for watching 16. 16 Speed Sensors Magnatic Pick Ups and Tachometers: the second time is the magnetic pickups. It used a very similar approach for optical type. These use on inductive coil placed near debilitating body. A small magnet on the body generates Paul's every time it passes the oil. If the body is made off Ferro's material, it would work without a magnet. As you can see, here we have the coil at the bottom. Here, Andi, here you can place either a magnetic or you can blaze a notch. Each time this notch buses through the big, big cup coil. It will change the magnetic field off This going on. This can be measured on each time that notch passes this pickup coil. It will generate a balls. The same concept applies here just like the previous one in. By counting the number of policies over a period of time, we can easily measure the speed at this. Continuity in the surface such as a notch will cause a change in the magnetic field and generate appalls. The boxes must be processed to produce on analog or digital output. The last time here is tackle meters. There are two types off Documentos A, C and D. C. The S e type generates essential the out boat just like this one. This is the A C time. The frequency of the voltage represents the speed off the rotation. So bending with a frequency off this a C type, you can convert it into speed using a problem equation. The frequency must be counted on processed in order to get a result. While the D C type generates a direct output, which is a voltage that is directly proportional to the speed, both guys must be coupled toe the irritating buddy. Very often the attack A meter is built into electric motors to measure their speed. As you can see, this is a mature with attack, a meter built and on. You can simply take y ours to measure the speed using this circuit, so it's already coupled with the shaft off that motor on. This is very common in the industry. Thanks for watching this lesson. If you have any questions, please asking that you want able have learning. This is educational engineering team 17. 17 Flow Meters Positive Displacment Types Intro: no one will come to this in your section in which we'll talk about flow meters. There are many hundreds of times flow meters. Depending on the make on application, they may be classified roughly as follows. Positive displacement types, influential types, variable area types on floated spiral gears. We will try to cover all of these four men sections, and you will cover all subsections as well. So fares we are going to talk about cost of displacement types. These types have a mechanical element that makes the shaft off the meter rotate ones for an exact known quantity or fluid. The 20 off Floyd hands depends on the number off revolutions off the meter shaft on the floor. A depends aboard the speed of rotation. Both the revolutions on speed may be measured with mechanical or lift running devices, some of the most common listed below. There is rotary piston type, van type, loop type or mission growth or this implicating personal time floated spiral gear. So now when we want to explain each of these their fall under the positive displacement types, the mission growth off type is one off the positive displacement meters, which is the fares type of flow meters. The machine growth or type consists of two rotors with loops when fluid, as you can see, comes from here The lot on stills. As you can see, this rotoworld fail on did intend. This river will tell here both of these rotors will turn on over the indicating system. Usually the indicating system is connected by a shaft to a point are on a dial on a scale. So this point will be a shaft on the shaft will move a point or on a scale to indicate the amount of floor. There is a lot of combination in which we can make this work. But again, this mission grotto is one of the most of this. A placement times. Andi, it works using two rotors with boobs once the floors and it will move these two rotors on. These two writers would move Abdul defined amount depending on the amount of flow which can in tow move a point on a scale to indicate the floor rate. After moving in, they were moved out toe Allow more flow or more fluid to flow. See you next s own Thanks for watching This is educational engineering team 18. 18 Flow Meters Inferential Type Meters: Now let's talk about the second type off inferential off flow meters, which is inferential type meters, an influential type meters. The flow off the Floyd is in fared from some effect produced by the floor. Usually this is a rotor which is made to spend on the speed of the rotor is sensed mechanically or electrical electronically on. There is only me and four types. The first time is turbine rotor type. The second is rotary shun type that there is rotating van type. The fourth is helical Torben types, and we're going to discuss two of these types. They follow another inferential type meters. The 1st 1 is the Torben type. This picture shows to industrial flow meters. As you can see, this is how the industrial shape off the turbine type looks like on this is it's schematic . The turbine type shown. This is how the schematic looks. The turbine type shown has an axial rotor which is made to spend by the flu. It, as you can see, this is the water. It has an axial shape. So when flow is in, it will cause that right or toe rotate on the speed represents the floor it. This may be since electrically by coupling the shaft toe a small electric tackle meters. Often this consist of a magnetic slug on the rotor. It can be placed here, which generates a bus off electricity. Each time passes the sensor so we can place a sense for here. Andi, let's say we can bless, like not here each time that I cannot pass it through the sensor that we can start counting buses over time to measure the speed off floor are getting. This is a shaft on. This is and I've zero tour. Once the floor is in, it will start rotating and it will go out. The rotation can be counted to measure the speed off flow or the floor it. This is the industry a trip. The second time is the rotating vein type, as you can see from its shape. Veg it off. Fluid spins around the rotating van so it will start spinning. Here. Here's here on tears and the speed of the rotor is measured mechanically or electrically. So there is one thing in common between all of these is that they all count on accounting the speed off floater to measure the flow rate or the speed or flaw as you can see you. So once the rotor rotates with the fluid, it will or it can be measured. Once the the water is rotated with the fluid, we can measure Ah, the rotation off this rotator toe to find out the speed off the flow or the floor. It next we'll talk about the fair dive flow meters, which is variable area tied. Andi, we'll discuss the floor type on terrible blood type. Thanks for watching this lesson. If you have any questions, please asking the few and able have been learning. This is educational engineering team. 19. 19 Flow Meters Variable Area Types: Hello and welcome this in us, in which we'll talk about the fare type off flow meters, which is variable area type. There are two men. Type off this meter, the floor type on the table plug type. We'll start with the floor type, as you can see from its name. It has a floating element, which is this element. Andi consist of this as a tube. The floor is inside a table tube. As you can see, it has a table chip. The fluid flows through them. Annual grab around the edge off the float. This is the float, so fluid goes around the grab. The restriction causes a pressure drop over the float on the brush our forces the float upwards so the float will keep moving upwards until it reaches a boring that the flu. The force off the flow equals the weight off the about blood or this symbol float. Because the tube is tabard, the restriction is decreased as the floor it moves up. Eventually a level is reached. Were the restriction. It's just try to produce a pressure force that continent to produce a pressure force that contracts the weight off the float. The level off the floor indicates the floor it. If the floor changes, the floor moves up or down to find a new balance position. And we can easily take the reading using the tabard surface by adding a reading level here just like this one. This is the industrial floor type. As you can see, here we have the floating element on it can movable down. Sometimes a spring is used toe ah, reduce the amount off force needed to stop the float. But eventually you got the idea. We have a fluid floating up on. We have a float that more that's try to move down. Once the force up equals the weight off the float down, the float will stop moving and we can see where it is exactly using on indicator on the edge off the tabard blood Andi Hence we can easily find the floor rate. The second time is tabled blood type. In this meter, a tabard blawg is aligned inside a hole or orifice. As you can see, this is the Tarbert blood. A spring holds it in place. This is the spring. It holds this double blood in the place. The floor is restricted as it passes through the garb. Andi, a force is produced which moves the blood so flow will come here on tourist. Start moving this terrible blood. Depending on how strong is the spring, it will keep moving that the spring until Krish is a point that whether flow power equals the spring force. So the tabard will stop at a certain location. Let's say, here on, we can easily get this reading up here toe find the floor it because it's doubled the restriction. Changes on the blood takes up a position where the pressure force just balances that spring force and the movement off the blood is transmitted with a magneto, an indicator on the outside. So both of that about blood type and floor type works on the very sale principle, and they follow under the variable area type category, which is the fare type of flow meters. That's it for this lesson. If you have any questions, please asking that you aren't able. I'll be more than happy to help. Thanks for washing. This is educational engineering team 20. 20 Flow Meters Variable Area Types: now to the fourth. I've off flow meters differential pressure flow meters. There are a range off meters that convert flow rate into a differential pressure. Then Borten types confirmed Toby US 10 for two on day are Dreyfus Meter. Eventually Meter knows l meter on. There is the 4th 1 that's called bitter Meet all, but it's not listed here. The diagram shows a cross section through the four types off differential brother pressure meters. As you can see, this is terror, right? First type. This is the nozzle because it looks like another. This is the better tied on. This is the eventually type, which is the most common type on most off engineering schools. Teach this type Each of these four types needs are separated course to explain its design, how it works and how to deal with it. But what you need to know is that each of these four types has to pressure meters as you can see p one on p on or will be too. Here should be beetle B one B two on the difference between beyond on Pito is measured using this structure. Now the working principle for all these is that something makes the velocity of the fluid change on. This produced a change in the pressure so that the difference Delta pressure equals P to pressure to minus pressure. One is created which is basically the difference between this one and this one p two a minus p one be to my last p one p two line Esperion on this is a direct relation to equals k the difference in Russia US 0.5 or to the power off 0.5. It can be shown for all off these meters that the volume flow rate que is related to the financial pressure Delta bi by the following formula, which is Q equals K little B to the power off 0.5. Que is the meter Afghanistan, so it's a constant for each of these four meters. A full explanation off these meters is covered in the story ALS or fluid mechanics or in fluid mechanics spokes. I can attach some of these tutorials in this section. On the big, this picture shows and just really fresher pressure meter extra instrumentation heads can be fitted to produce on electrical output off for toe 20 million arms or on U Matic Out boat from 200.2 to 1 bar. So depending on your needs, you can add extra equipment. If you need digital reading that follows the standard. But what you need to know is that this equation is what governs the amount of flow. Andi. It uses the difference in pressure between Peter on B one to measure the flow rates. That's it for this lesson I would attached with some material. If you need toe, gain more knowledge about these four times again, they are very, very complex on there. They need a lot of time on this course. Isn't just for flow meters. It's for all time sensors, but for you just need to know that these four types exists on dwell. Once you need them. I will add resources for you to learn more about them. Thanks for watching this. Quick plus on fuel. Have any questions, please? Asking the few under board. If you need more specialized information, please send me a message. Thanks. This is educational engineering. 21. 21 Force Sensors: four sense ALS. There are men types for four sensors. The 1st 1 is the mechanical time. The second is the hydraulic types. The fair is electrical strain gauge type. Let's start with the mechanical type. Mechanical types are usually complete measuring systems involving some form offspring, such as in a symbol, spring balance or bathroom scale. It's a basic mechanical principle that the deflection off a spring is directly proportional to the blood force. So if the movement is shown on a scale, the scare represents force. As you can see here, this is a spring on. This is where you're going toe, hang the force or wait. And here we have a pointer on a scale. Now, as you are blind force or wait here, the spring will move that in that direction on the point or will move in that direction, indicating the amount of applied force using the point or on scale system. It's a very simple and very straightforward It's yours. The man principle, which is the deflection on a spring, is directly proportional to the applied force. The second time is the hydraulic type. Hydraulic types are often refer to as hydraulic load cells, the city is a capsule filled with liquid, just like this one. When the capsule is squeezed using a force that comes from up here, the liquid becomes pressurized so this liquid will become brush allies. Andi, it will falls a point are to move on a scale to indicate the amount off pressure the brush represents. The force on may be indicated with a calibrated brush. Our gauge the capsule is often a short cylinder with a piston on the brush. Are produced is given by the question. P equals force. Pressure equals force that divided by the area. So a is the Beeston area. This area and F is the amount of force applied on this will result. One will give us pressure as a final resort. The next thing is string Gische. Staying age, which is the third time off four sensors is a device that gets trend and in little, it reflect that strain as voltage or current. A typical load cell consists off. A metal cylinder holds strain gauge. Fix it to it when the cylinder is stretched or compressed. The strain gauge convert the forced into a change in resistance, and we already explained this concept in the strain gauge less one, and hence the resistance is converted to voltage. Since the elements requires a supply voltage, the sill usually has four wires, two for the supply on to fourth output. Usually this thing is is blazed in this area. On when the force is applied, it will strain the surface, which will increase the resistance. And once the resistance is increased, the final result will be that this area ah, is stretched on. There is a sense can be converted toe voltage using arms law. Next, we'll talk about positions in source, so stay tuned. He's 43 types of four cents or are very easy to understand. The 1st 1 is the mechanical time Assemble deflection of a spring, the hydraulic Taib, using the P equals F divided by a implantable on before the fair type is the strain gauge type that use resistance. Ah, that gets strained, then stretched, which increase the resistance and as a result, we can turn this into a voltage. Thanks for watching this quick lesson. This is educational engineering team 22. 22 Position Sensors Resistive Type: Hello and welcome to this annual Asan in which we will talk about position since ALS position sensors are essential elements in the control off actuators. The position off pull both linear and rotary actuators is needed and robotic type mechanisms. There are three principal types the resistive, the optical on the inductive position sensors. We will start with resistive types. A potential meter is variable variable electrical resistance. A length off resistance material has a voltage applied over its ends. So just like in this example, we have zero volt on. We have 10 volts. A slider moves along it. This is our slider that moves here and here, either linear or rotary. In this case, we have to voltages zero volt involved on this is the motorist lighter and picks off the voltage at its position or anger. So in this position, we can get a voltage on In this sport angle, we can get a different voltage. The tracks maybe made from carbon resistance. Why are or bees or resistive material? I would again, the latter is the best because it gives a good on a look out. But which is the bees? Oh, resistive material. The way I want. I produce small step changes in the output depending on how fine the wire is on how close it is gold on the track. This is the first types and it's a very east understand, on common type. Most of us dealt with potential meters. They are variable electrical resistance. So depending on the location, if you are standing here regarding the position, the output will be to say, seven volts or six volts. If you're standing right in the middle, the output will be five volts. If you're standing here, that will be zero volt, so few mature falters on, got the revolt. You know that you are standing at this location. If you measure the voltage on, got 10 volts, you will know that you're standing in this location. If you got the voltage reading on, you got five volts. You know that you are standing here. Same applies here, but instead off linear placement. This is a rotary placement, so we will get degrees instead of centimeters on. This can be applied to any type of devices. That's it for this quick intro on for that is stiff time position sensors. Thanks for watching This is educational engineering team 23. 23 Position Sensors Optical Type: Now let's talk about the second time Off position sensors, The optical types, optical types comes in two different versions. A linear on the second version is a rotary. The seniors time in optical types are mainly used for producing digital outputs. A common example is found on machine tools Where the Mitchell supposition off the work table on displayed in digits on the gauge head. There's that micro meters on. Vin burners also used this idea. The basic principle is as follows. Light is emitted through a transparent stripe. As you can see here, light is emitted from this light emitter. Andi, this in this case in the senior light, is emitted from the light meter into a transparent Streib and is reflected toe the receiver . As you can see from that transmitter. That s evil. Now this is the stencil head. Okay, on this is the engraved threat. This is the middle to reflect the light. So down here we have a mirror. I'm here. We have a Streib that has engraved Oh, places where light can be reflected on depending on how money policies where created. Using the sensor head, we can know the exact location. Now the sensor head is here, and let's say that we have one toe. 34 You can see that this is the 1st 1 Second one failed one on 4th 1 So if we have four balls is this means that we are at this location now. If we kept moving as we keep moving, the sense that it will keep transmitting and receiving bosses as it passes through each of these graves on DE, depending on the count our value, we can know the exact location where we are now. When it comes to the rotary type, rotor types can produce either absolute or incremental measurements. Incremental. Use a disk with slots in it as shown as you can see, this is a disc. This is the first slot on. This is the second slot. As the disc resort revolves, lie sensitive detectors bicker blight from two sensors, and as the dis revolves, a series of pulses are generated. The angular original position is found by counting the policies. So depending on how many bosses there, we can know the exact location off this shaft. Because the two detectors are offset by one slot. As you can see, one off them is here on the other. After it, the two sets off vaults is displaced in time. As you can see here, this is the first set of all sizes in this area. And after a bit of time, the second set of balls is thoughts. This enables the direction of rotation Toby through mind by checking the order in which the on off changes. Okay, so these two are used to know if we are moving left or right in the desk. Now, this is the incremental in quarter, but the absolute in quarter works using a different better absolutely include argues. For example, four rings, as you can see here. 1234 four rings on the desk. Divided into bake and transparent sectors. Four detectors are used to produce a bindle additional court for each sector. This produces absolute code for each position in the form of four bit number. As you can see for if we got this cord, we know that we are in this location Now if we get another cold like this, one for ones will know that we are on this location. This is one type which is called the gray scale. The second time is the old dinner scale. Now the difference between the the stool. They both fall under the absolute encoder for measuring for optical measuring supposition that the great quoted scale is usually preferred because only one bit changes from one transition to the next producing list, like hold of switching errors. If the disk revolves more than once, that evolution must be counted as well. So in this case, this is more accurate than this one and uses for bit better, which results in more clear, ah, results, and the errors are minimized. That's it for the second time, which is the optical type. Thanks for watching this lesson. If you have any questions, please ask. Thank you and a board habil early. 24. 24 Position Sensors Inductive Type: Now let's talk about the fair time, which is inductive types. The most common of these is the linear, valuable different child. Transformer or insured. Alvey DT. The transformer is made with one Bry Merrick oil, which is this one on to secondary cords, which are these two one placed above. On the other below the Brymer, the calls are formed in tow, a long, narrow hollow, too. As you can see, this is the structure. It's like a whole little magnetic core slides in the tube and is attached to the mechanism being monitored with a non magnetic steam. Or plus, as you can see this one, let me just change the color. This is the green one. This is the core now, depending on the core location. As you can see, this is the hand that moves the court. A constant alternating voltage is obliged. The primary coil, this induced voltage in both secondary coils. When the core is exactly intimidated, equal vaulters are unused and when connected as showing the cancel each other out. When the core moves, the voltage in one second record grows but reduces in the other. The result is an output voltage, which represents the position off the core and hints de mechanism toe, which it is attached. The output voltage is usually converted in tow, D. C. So that we can easily deal with it. This is very simple on. Let me summarize this to you. No, here we have a primary call on to second record. The primary takes a voltage as in boat. Now this score moves from here to here. Now, if it's at the middle, the voltage from the primary call will go to both of the secondary coils because we have magnetic field. The relationship on these since the calls in exactly in the middle, the voltage will be the same, and they will cancel each other. But if we did move this core up or down, if we did move the scoreboard down, the voltage will increase in one and decrease in the second, which would affect the final output. So, depending on the final out, but we will know where exactly is the core. If it is in the middle, that outfit will be zero on. We will know that it's exactly in the middle. That's it for this lesson. These are the three times off. Ah, Optical off position Sensors Optical. Taib. Andi Resistive Type on. The last one is the inductive type. If you have any questions, please asking document able. I'm here to help. Thanks for washing. This is educational engineering team. 25. 25 Depth Gauges: hello and will come to this annual Asan in which we are going to talk about depth gauges. Deaf Ganges measures the depth off liquids on about our in tanks. They use a varity off principles on produce, out boats in electrical on dramatic forms. The type to use depends on the substance. In the time on Dhere is a few. The 1st 1 is the ultrasonic level gauge. The ultrasonic system reflects sound waves from the surface, and it reminds the depth from the time taken to receive the reflected sound. The electronics very news severity of electrical effects, including conduction off the fluid on Galveston's. Then you magic version bubbles air As you can see air pressure system. This one bubbles air through the liquid on the Russia off the air is related to the depth. Assemble. Pressure gauge attached to a tank is also indicates the depth. Since this is since depth is proportional to pressure, the fair time is pressure gauge system. You can simply place a brush our gauge here at the bottom off this tank to measure the amount of water in the tank. That's it for this is, um, thanks for watching. This is educational engineering team