A look inside: Wind speed and wind direction sensors, scientific measurement instruments

hello again youtube this is a what's known as an anemometer it's a piece of equipment that sits on top of building and it catches the wind and these little cups and it rotates and it tells a computer how fast the wind speed is outside this is an important piece of equipment if you have windows that are open in a building maybe they're open on the roof and it starts to get windy outside then a piece of equipment like this is important to tell the computerized system that the weather's not so good and it needs to close the windows to prevent damage normally i hide brand names and model numbers but this one i don't mind showing you because i believe this is obsolete that's uh the company don't appear to make these anymore and this is a i'm sure they wouldn't mind me showing it because it's a very high quality piece of equipment and it has failed but like i say it's a good number of years old and i'm pretty sure i know why it's failed in fact you can probably see some evidence here of why it's failed i'm fairly sure it's weather beaten but you can tell straight away you can tell from the weight of it um it's quite a heavy piece of kit a lot of that weight is going to be on the aluminium body of it i'm pretty sure this is this will be a milled piece um that's a fairly chunky piece of aluminium but we'll have a look inside let's even get it open we'll take a look inside and see why it's still working okay so i can see in there there is some let's just pull that cable out there is some evidence of rust and net so i had a an idea that water was the issue um that's because this should spin quite freely but if you listen bring the microphone up that's not that's not free there's a lot of friction there there's a lot of squeaking going on so i'm fairly sure the shaft somewhere down here has corrosion water's gotten inside um and that has caused this to fail over thing if i grab one of these and you can see there's a lot of corrosion in there it's a lot it looks like powdered rust it's a very thick powder so we'll check this out in detail but i'm fairly sure what's happened here is water's gotten into the top of the shaft possibly through the grub screw that holds the cap on it's then gotten down into the the neck and something in here whether it's a a washer or a shim or maybe even the shaft itself we'll find out in a minute what it's made of but it looks like something's started to corrode because this spins and you can hear it's quite squeaky the squeaking noise comes from friction and that friction has probably powdered the the oxide that's formed and it's dropped down onto the circuit board so that's what's stopped us working um this is the first time i've looked inside one of these but i can see there we are so we can see there it looks like an led so i'm fairly sure this is going to be some form of optical rotary encoder because it looks like there's a disc in here it has teeth cut from it so as this spins the led there will be a receiver on the board and that's more than likely counting the pulses as the disc predates but let's see if we can strip it down a bit further get a look at separate the two components and have a look at each of them and see if we can find out what's gone wrong okay so we can see there's quite a lot of oxide on the top of the board and i can see from here there's a little pinhole through the board a bit bigger than a pinhole but that'll be the the optical receiver so the led will transmit light and the receiver will receive it in there so when this stopped working two things happened initially it was initially it was a reporting that the wind speed was lower than it actually was so i think that was because the shaft here had accrued quite a lot of friction so it wasn't spinning as fast as it could have and then it stopped reporting altogether and i said the wind speed was zero and it's quite likely that what's happened is this little hole where the receiver has filled up with this dust so it wasn't able to see the pulses anymore so it probably just thought one of the fingers on this disk was sitting over the top and it was it was a stopped so let's see if we can get this off okay so this is just a little disc it looks like it's just uh some sort of steel it could be wrong um but it looks like steel it's maybe nickel coated there's no there's very slight corrosion in the center here around the screw hole some very slight corrosion there but other than that the disc itself doesn't have corrosion the fingers aren't corroded you can see that the rust is going all over my fingers but it's not coming from that i think some of us gathering on there i'll just put these aside so it looks like to get into the shaft i need to get either the base or the top off now the base this little washer i think is a shim or a bush it's just rotating um oh yeah this is this wants to come off so that looks like a brass standoff so that's that's fine that's not corroding this looks like aluminium again it's brown because there's a powdered uh steel rust on the iron rust and then this wants to come out so we've got a little bearing here and before i go any further let's see if i can feel if that's oh that bearing's gone it feels really rough you might [Music] be able to hear it but yeah there's a fair amount of corrosion on the balls and that bearing so that's failed you probably again will bring up the microphone you can feel that bearings also going that's crusty as hell so the bearings have failed that's been the main failure mode that's what's caused the unit to stop working um but what's led to the bearings feeling appears to be some form of water ingress that looks like the end of the screw and i think it's snapped off so getting this white powder here um that'll be a mixture of rust from the screw and a bit of oxide on the aluminium because it appears that that's lost its head now i know this one's lost its head and because that when i was initially diagnosing the fault i tried to remove the screw and the head came off straight away and that's because the the corrosion had already taken a good hold here so i could try and drill these out um but i'd have to put that on a bench drill and i don't have that here so that's maybe a job for another day i'm gonna have a look at the board now see what's on the board and before i do this i need to apologize if you hear a lot of wind noise it's getting stormy outside and i do my filming in my shed outside so there's not an awful lot i can do about that so apologies in advance um so let me just grab a chopstick um the board this side of the board is populated with a few components this side of the board all it has on it is this infrared emitter um so the active component on here is this this little black and gold chip here and this infrared transmitter and you can probably see on the board there is designated tr1 and on the other side it's also tr1 uh it's also got led so in fact this is le led1 oh yeah led one so it's a light emitting diode but it's likely that and that's infrared light and then underneath here there's a tiny little hole in the board so you can see that yep just there so the the disc that we saw earlier this disc here as that rotates the fingers on it block the light passing down through so this parts the transmitter underneath the receiver that's the that's how it measures the wind speed and creates the pulses so if you look at these two here this pair of cables are the power so you've got uh this takes between 6 and 26 volts dc so quite a wide power range you've got two big diodes here and a few supporting components uh they'll be there for uh polarity protection just to keep the device safe in case you accidentally switch the polarity around um this little chip here this is a this is an mic so it's a microchip two nine five one it's a linear regulator it's a five volt regulator which then provides the the power the smooth power so you've got a couple of little capacitors here as well they'll be to smooth the output focus um the way to smooth the output for this set of components so this is the active circuitry and you've got a little chip here now this chip's a cmos comparator and the model number on it let's see it's got conformal coating so it makes it difficult to see but the model number is an lmc67 and it's a cmos comparator and basically it takes the signal coming off of this component of this transceiver and it converts it into a five volt pulse so instead of uh you know you might imagine as this this is passing it's passing pretty quickly you'll have um fluctuating voltage levels will almost be like an analog waveform so this will compare it and then it'll convert into a nice 5 volt square wave and that square wave signal comes out of this yellow cable and that goes off to whatever you're going to use to measure the pulses so that's that's how that one works on this particular job that signal then goes into this here this is a part of this pair of sensors so this one measures the wind speed that's the the vein a moment sorry the cup anemometer this is a wind vane so you probably uh see these something similar to this on top of old churches where you've got maybe a you know a picture of a cut out of a so it will be a an old-fashioned weathervane this is a modern equivalent and this plate here is the equivalent of that that the bird that catches the wind the purpose of this is this will trail in the wind and this bullet part in the front will point into the wind so if the wind's heading straight down it will go like this and then you can measure the rotation of the wind so where the wind's coming from and this unit will output that as a signal this is quite clever because the way this works is it takes the wind speed in on one of these cables it takes the wind direction and then it puts it out on another cable um it's actually got more than one option you can this also puts an analog signal as well and we're gonna have a look inside this in a second so you can have a look at how it works so again we have a two-part device we've got the part on the top that rotates and again it's a very very similar construction to the the anemometer the same sort of case and these are these are milled from a single piece of aluminium and then the o-rings inserted the bearings inserted so they're actually quite heavy it's a very high quality piece of equipment you'll notice there's a hole drilled here and on the bottom of the case you've got two little holes drilled and they're roughly in the same orientation there's a good reason for that because uh they tell the device which direction is north there's a sticker here as well that used to say n but it's been sun bleached so the little holes here they determine where north is and that's important because when you put this up on the roof if you don't point if you don't know which way is north then when you take a reading from it that reason is going to be wrong so what we have here is again you've got a rotating shaft that when it comes down through this bit rotates here this bit as a magnet um let's see if we've got something that's yeah magnetic so um it's polarized in fact let's say grab a screwdriver and see we can yeah so that's north which is that's north of the magnet which is uh pointing straight forward so and then the other one will be south so yeah see how the the tip of the screwdriver's drawn to one end of the magnets it's either north or south here um now again that's important and if i was to take that off there probably are markings on here for reassembly um but possibly not i mean effectively you don't want to take this off if you are going to take off you know if you've got one of these you're going to take off put a mark on it before you do that because otherwise your rotation is going to be wrong so put this aside for now so this part here this is what we're interested in um we've got a bit more circuitry on the back here we've got this this big chip here just discharge myself before i touch anything um we've got a chip and that chip let's see there's a it's a pick you can probably see it better than i can it is it's a pix16f 873 so that's a that's a microcontroller it's a programmable microcontroller um enough in fact yeah there you are i saw a header on the board here so we've got a little five pin header so that's probably for programming that chip we've also got a crystal on here um the oscillator so that's needed for the chip but it's uh that alludes to how this then communicates with the panel um now i've already had a look at the the spec on here i know how this works um but the fact is a crystal tells me that this is doing serial communication the way this measures the the wind direction is this little device here so it's a little six pin component there are no markings on it i've had a good look at already um there might be markings underneath but i'm not going to take off but i know what it is it's a hall effect sensor and the way this works is as this magnet rotates above there the the hall effect sensor you probably have two sensors in here so normally a hall effect sensor just detects the presence of a magnetic field but you probably have uh two sensors inside this unit and they'll tell you the strength of the field so you'll you'll be able to tell which direction this is facing in and so this will be maybe effectively a whole array because it does 360 degree rotation um and that that's pretty much it that's the that component there as the single component measuring the rotation on top of the the board you've got the the main processor we've got a crystal and then we've got a couple three smaller chips here again we've got a linear regulator so to to smooth and control the the five volts that's driving the rest of the board and then we've got a couple of little op amps um and they're pretty much there because the once this has done its thing uh you're looking to amplify the signals you've got a signal coming in from the other unit and then you've got the signal coming out from this so the op amps are there to manage those analog signals so again we've got we've got two cables for voltage in this case is black and red the blue cable here takes the input from the other unit so from the anemometer so we connect that to the output of the anemometer and that brings the analog signal in the the five volt pulses we've then got a weight cable which is uh the ground for the signal and then we've got two signal cables uh so they both they're both the reference to this white cable the ground so the yellow cable is the analog output that 1.8 volt output so get rid of that one the other one we're interested in is this one that's the the green cable now this little pick chip is programmed to output an nmea signal it's a serial signal and the nmea i can't remember exactly what it stands for it's uh nautical and marine equipment association i believe and it's a standard it's a serial signal it's a standard that's recognized by a lot of equipment that was designed for use in boats and obviously wind speed and wind direction are really useful when it comes to boats so this is a device that's probably quite commonly used in the marine environment certainly from the quality of it when you look at the the o-rings that are in play and um it would suggest that it's designed for a modernized environment it's a very high quality unit um now using this arduino uno uh and i've got this board on it it's not a shield it's just an rs232 board i've got it just has got a little max 232 chip on it okay i now have my two sensors connected correctly through my max 232 interface and onto my arduino board and if you have a look here you'll see there's a pulse happening here that's happening four times a second and then on the arduino board just down here under that cable there's a similar pulse and if your eyes clean enough you'll see there's a very slight delay between them because there's a processing time between this unit and this unit so all in all it's you know we're talking milliseconds here so it's not going to make any difference to the the operation of this sort of circuit um now no matter what i do these sensors that pulse isn't going to change because it's a serial pulse it's the what's happening with the interpreting the wind speed and direction has nothing to do with how often this transmits if i was to measure on the other cable so on the yellow cable from the from the weather vane and directly off of this yellow cable then that'd be a different matter because i'd be looking for analog pulses but in this case it's just all serial okay so here we have the output from the serial output from the sensors so this is coming from the the wind vane and you can probably see there we have well a bunch of characters um and they don't really mean much to us it doesn't it doesn't really do well for a human um you've got a dollar and then mh was you've got that repeated and then you've got some values uh you've got an r some zeros and an n then you've got wsd then some values and then some other numbers now those contain the information coming from these two sensors and if i rotate the weather vane you see the values are changing um now and if i take the anemometer see we should get some some more values changing but again it's a it's a bunch of random numbers so it doesn't doesn't read well very well to a machine that reads well uh in fact one thing that's quite obvious there you see it as you rotate if i rotate the the wind vane we've got l changes to r so we've got left and right now i would imagine that would be designed or that code would be in there for a nautical environment so that you know whether you're prevailing winds coming from the port or the starboard side of your ship um so that might just give a a simple system an input that just you know gives a mast an instruction to move um so but for us we want to be able to read it so um what i'm going to do is i'm going to change the code i'm going to make the code a little bit more complicated and see if we can pull out the relevant figures and see if we can make it make sense to us so what we have now in the small screen this is the arduino serial monitor and you can see i've got two values i have wind direction and wind speed so at the one direction at the moment the same one two one if i take the the wind vane and my north is here let's say there's a sticker there so that's north so if i point it north the wind direction should either go to 360 or zero so there we are there we are so that's it due north so we're at zero three five nine or zero um if i rotate it round let's just rotate it around the other way should go roughly 180 yeah 198 195 182 so as this spins about in the wind you'll get varying uh figures back on that value so that tells your your system which direction the wind's coming from the other unit now this this isn't working very well because it's got no bearings in it but if i rotate this you'll see that value for wind speed starts to rise we're up at 1.3 1.4 and if i start to rotate a bit faster up to 3 4 5 so that's measuring in meters per second and you can hear that was probably here that was quite noisy because it's missing his bearings and as i'm rotating it like that i'm probably doing some damage i hope you found this interesting from time to time i do take apart things from my work life and they tend to be things that most people don't see on on a day-to-day basis and something like this most people won't see in the life so if you did find this interesting and you want to see more please subscribe to my channel and if you enjoyed this video give me a thumbs up thanks for watching i'll see you in the next video

Channel: Craig Childs

Views: 2,896

Keywords: anemometer, weathervane, windvave, wind vane, wind, windspeed, wind speed, weather vane, NMEA, NMEA serial, serial, communication, arduino, scientific, instrumentation, scientific measurement, weather, meteorology, meteorological, teardown, opening, look inside

Id: gYSysL6Nwhc

Length: 26min 36sec (1596 seconds)

Published: Sun Mar 28 2021