### Measuring Volume

So im doing a science fair project for my school and i decided to be different from all the projects. im connecting a 2 channel amp to some old speakers and i was wondering how to measure volume or loudness coming from the speakers when i increase the watts of the amp. my teacher told me theres a specific unit for this and and specific way to measure volume. but so far i cant find much. so i ask you guys for help. please and thanks.

Posted by gpiejai 11 years ago  |  last reply 11 years ago

### Measuring audio

I have a project where I need to be able to measure 3 or 4 microphones and decide which one is getting in the loudest input volume. In other words to know who is talking around a four persons table. Does anyone have any idea how to solve this problem? I'm using arduino (http://www.arduino.cc/) for the rest of the project so I'm able to use the arduino to measure dc voltage but how do I transfer the sound wave into a measurable dc voltage? thx in advance / david

Posted by ZrvZ 12 years ago  |  last reply 12 years ago

### Measuring an explosion

While this may not be the best instructable I believe it would be helpful for many people doing science fairs (ie: ME). So here is the question said instructable would answer: How do you measure the force of an explosion, specifically of gases or liquids used in fuels? I have been racking my brain on this but everything i have come up with seems like it would be inaccurate. Thanks for any help

Posted by durp123 9 years ago  |  last reply 9 years ago

### can I get the value of an inductor with a resistance and capacitance meter? I don't have an inductance meter.?

Asked by m.m.m 5 years ago  |  last reply 5 years ago

### laser measuring of atrifiact? Answered

I have a friend that needs to make a duplicate of a fragile archeological artifact for further examination. He only needs the face, a single surface, measured and duplicated. I thought of a two technologies project. First a 3D measuring of the surface then a 3D printing of the results. Have we done such a project?

Asked by kbs2244 6 years ago  |  last reply 6 years ago

### How to measure capacitance?

What is the most inexpensive way that I can measure capacitance? I have some photoflash capacitors that aren't marked with their capacitance. I went to radio shack, and the cheapest multimeter that measured it was around 60 dollars. Is there a cheap way that I can find out the rating of my capacitors?

Asked by daa5849 9 years ago  |  last reply 6 years ago

### Measuring LED Voltage

Greetings... I have quite a few "salvaged" LED's, none of which have I the slightest clue as to their voltage. I have attempted to measure them using the diode setting on my voltmeter with dubious/mixed/questionable results. Although the measurements are momentary (the reading is barely of sufficient length to note), I can usually arrive at a value. Unfortunately, when I repeat the measurement on the same LED the reading is invariably different. For example, I just measured the value of a random LED (green) and came up with the following: 1.3. 1.4, 1.8, 1.6. I've rounded the values to the nearest decimal point. Are these values through voltage? Are the differences between the readings significant or should I use the minimum when calculating resistor values? I'll, no doubt, have a few more question later on. I appreciate your elucidation on this matter... Best to all, hassi

Posted by hassi 10 years ago  |  last reply 5 years ago

### Current measurement with arduino

Hey I try to measure current with hall-sensor amploc 25A, it sense magnetic-fields, offset voltage is 2.5V and I use arduino uno. I get 519 value from analog pin and 37mV/A is hall sensor sensitivity. My formula is outputValue = ((((sensorValue*5000.0)/1023.0)-2500)/37 multimeter shows 0.112amps when I put load but I dont gett correct value on LCD Is my formula OK?

Posted by mattilaniko 3 years ago  |  last reply 3 years ago

### Sensor to measure weight.

Hi everyone, I am stuck. I am trying to find a method or sensor to do what I want. Basically, I am trying to make a cheap flat weigh scale- light weight , flexible and portable (carried in a brief case or lap top case); thinner than using load cell sensors. I was hoping for a flat compression fabric , foam or piezo resistive pressure sensor, but have not found what I was looking for. It needs to be able to measure 50 to 250 lbs & fit on a counter. Does something like this even exist? Any suggestions would be most welcome. Thank you Appl314

Asked by appl314 7 years ago  |  last reply 7 years ago

An article in PhysicsWorld reports on a novel technique for measuring the acceleration due to gravity. The researches used a cloud of ultra-cold atoms and bounced them off a series of upward laser pulses. By measuring the timing of the bounces they could measure g with better than 1 per mil precision.

Posted by kelseymh 9 years ago  |  last reply 9 years ago

### Slope Measuring

I'm interested in making a yardage book for one of the golf courses i play at. The only problem is that i don't know an accurate way to measure the change in distance through elevation. For instance if a shot to a green with no change in elevation requires a 7-iron, then a shot of the same distance that is downhill should require a club that will hit the ball a shorter distance.       My question is, is there a formula of some type that i can enter the rate of change in slope and the distance, and get the actual distance needed for the shot.

Posted by wenpherd 7 years ago  |  last reply 7 years ago

### how can I find the relative between the angle and volt to calculate the angle with pot?

Asked by ertebatbehineh 7 years ago  |  last reply 7 years ago

### How do I take a contour off my balcony railing and transfer it to a piece of wood?

I have a planter designed to fit over a piece of 2x4 railing, and a railing on my balcony that is smaller than 2x4, and curved, with a non-rectangular side profile. Please see the photos. I have annotated the first three photos. It's hard to see from the photo of the railing, so I drew a side profile of the railing shape and photographed my drawing. The planter has a groove in the bottom so that it'll rest securely on the 2x4. I want to make an adapter out of wood so that the planter will rest securely over my railing. I plan to cut some wood to fit perpendicular to and against the railing, countoured to fit over the railing, and seat a piece of wood over the top of the railing, running parallel to it, to seat the planter into.

Posted by Mr_Liss 4 years ago  |  last reply 4 years ago

### How do I measure for getting chair rail molding level and straight on the wall ?

I am going to put up chair rail molding in my living room and I can't figure out how to make sure the molding around the room will look straight and level all the way around the room. Do I measure down from the ceiling every few feet around the room or do I measure up from the floor every few feet to get it even around the room. Its an old house so I'm sure the floors are not level or square. Help! Thanks, Donna :-)

### Measure current and voltage with arduino? Answered

How would I measure the voltage and current of this circuit with an arduino?

Asked by flybye22 8 years ago  |  last reply 6 years ago

### Measure Punch Force tool

Hi All, I do understand we all keep creating new electrnoic tools/gadgets everday. But anyone had tried to create a tool which can measure force / intensity of human punch. It is fun to measure your punch force among friends. also if help us to improve your boxing strength. Please share your thoughts on it. Thanks

Posted by VinitV 1 year ago

### measure distance with raspberry pi?

How should i measure 10 meter distance very accurately with raspberry pi ?  if anyone knows any sensor that can measure distance of 10 meter accurately please tell me then i will manage ? thank you.

Asked by dharmik123456 2 years ago  |  last reply 1 year ago

### electronically measure poundage of an impact?

I'm looking to make a training device that measures the pound force of impact from a strike. I'm sure the is a sensor out there that does this but I don't know what its called.

Asked by wgriffith 1 year ago  |  last reply 1 year ago

### how to measure frequency in this circuit?

i want to measure the frequency of this flasher circuit but i always get a frequency close to that of the mains. I am using a wall wart. i changed some of the components to speed up the flashing but the frequency reading stayed the same. to check my multimeter i tried measuring the frequency of mains and the joule thief circuit and it looks like my multimeter is good. how should i measure the frequency in this flasher circuit?

Asked by codestroy7 7 years ago  |  last reply 3 years ago

### How to measure light wavelenght? Answered

Please, don't say 'with a waveleghtometer' . This is a Physics 'practical problem', and I'm thinking interference.

Asked by gruffalo child 8 years ago  |  last reply 8 years ago

### How to measure electromagnet by Tesla?

I will be doing an experiment how powerful the magnetic field of an electromagnet, and my guess is the more you twist the wire the more power it generate. But i don't know how to measure the magnetic field by using the unit Tesla.

Asked by defineSCIENCE 2 years ago  |  last reply 6 weeks ago

### How to Measure From a Picture

I am trying to make a table from a picture in a magazine, which has some intricate lathe work that I want to duplicate. The problem is the picture was taken at an unknown angle, and when I try to scale up from the picture my measurements come out screwed up. Is there something I can do that we allow me to find the right measurements?

Posted by Sedgewick17 10 years ago  |  last reply 2 years ago

### Measuring the piezo transducer with oscilloscope

Hi, I am conecting a piezo disc as a microphone to pick up vibrations. .The problemm is when I measure the signal with osciloscope I am getting a messy and modified one with many noise  If I am measuring it with PC oscilloscope (threw the sound card mic input) I am gatting a clean desirable signal What is the true signal and what I am doing bad with the oscilloscope. Thanks! Anna

Posted by AnnaL3 3 years ago  |  last reply 3 years ago

### Power supply amp measurement?

My power supply says it can supply 12 Volts @ 10 amps.  It used to power 2 linear actuators drawing max 4.6 amps each, but no longer does. It still supplies 12V measured by multimeter. Is there an easy way to figure out how many amps it now supplies?

Asked by thisisted 2 years ago  |  last reply 2 years ago

### Measuring oscillation of a multi tool

I have a harbor freight oscillating multitool that is advertised as oscillating between 10k and 20k oscillations per minute. In reality to speed control goes from 0 opm to an unknown value. I’m trying to set the tool to oscillate at 35 Hz. What is the best way to measure the frequency of the tool and set it to 35 Hz?

Posted by rednax718 10 months ago  |  last reply 10 months ago

### How to Identify or Measure Inductance?

I am gathering the parts for an ible, but I am short one part: a 12mH inductor.I can spot some inductors in electronic garbage - the wire coiled around a ferrite loop - but there are also solid state inductors. Plus, the inductors are not usually labelled with their values.How can I measure the inductance of an inductor with a volt-meter and an ammeter, but without access to a sine-wave generator?Is there some simple trick that would get me "close enough" to the true value? What would be really useful (but probably doesn't exist) is a chart or formula where you plug in the size of the core and the number of turns around it and out pops the inductance value. ?

Posted by Kiteman 10 years ago  |  last reply 5 years ago

### measuring petrol/ethonol accurately

G'day All, If this has been done before, I apologise, but I have not found anything when I have searched. I am a team manager for a team of students who need to design, construct a three wheeled vehicle. The test is a 24 hour "trial" (more like a race ;-) ) We have been competing in a category for "Hybrid Vehicles" which an additional power source to asssist the rider.  In our case it is a 50cc engine using a friction drive arrangement so we can disengage it if required or if we desire.  The reason for this is that we only recieve 3 litres of petrol for the event............  This is my problem.  I have not been able to measure petrol in the tank accurately enough.  Over the last two years I have had one litre left or ran out after 21 hours.    I have been thinking of using a strain gauge or load cell to measure the weight of the tank.  I'm thinking it could be as simple as powering up the load cell with the appropriate voltage, and measuring voltage drop across it, maybe with an added resistor. Or it could be made more complex by using a circuit to drive a number of LED's giving an indication of the fuel in the tank. If anyone outhere has any ideas to do this simply and reliably, I would love to hear from you.  If it is more complex then so be it. Here is a link to the event to give you an idea of what it is about http://racvenergybreakthrough.net

Posted by coln72 7 years ago  |  last reply 6 years ago

### Measuring a Bluetooth modules output? Answered

There is a serial Bluetooth module that I have used before on an Arduino project but now I'm trying to use in a project without the Arduino. Basically I need it to be an electronic trigger, I don't care really what the signal is just how long and the voltage and current. There are 4 pins on the module: Vcc, GND, Tx, and Rx. There are 2 open pads: Key and State. When I send a command from my phone the module sends a signal out the Tx pin, and it is this signal I would like to measure so I can pick a command with an appropriate signal and tailor the rest of the circuit accordingly. I tried a voltmeter between Tx and GND but saw no signal on any level measuring DC. Is there something I'm missing? Is the signal more complex or different, or is that test setup flawed? I tried other combinations, Rx-GND, Tx-Rx, RX-Tx, GND-Tx, GND-Rx but saw nothing.

Asked by bwrussell 6 years ago  |  last reply 6 years ago

### Measuring Current of 24v dc motor

How to measure the max current of 24v dc motor.. please give me step by step guidance. many thanks

Posted by epple 7 years ago  |  last reply 7 years ago

### 12v DC battery amp measurement? Answered

HI, I have a 12v dc battery and I wanted to measure the amps. Can anyone show me how to hook up the multimeter? Thanks

Asked by amantux 7 years ago  |  last reply 2 years ago

### is there any way to measure rpms cheaply?

We are making wind turbines in one of my classes and my team is making a tesla turbine as ours. we want a way to measure how fast the disks are spinning. please help.âº

Asked by DehLeprechaun 7 years ago  |  last reply 4 years ago

### create "black body" and measure radiation

Hi i have been looking for some experiment about black body radiation how can i make a black body at home and how can i measure the black body radiation using inexpensive materials... i would like to measure plank's constant and so... i didn't find anything on the net any suggestions? thank you!

Posted by yitzik25 1 year ago  |  last reply 1 year ago

### What are the measurements of the frets on a Mcnally Strumstick?

I want to build my own strum stick, & can't find what the lengths in between each fret should be.

Asked by jclay422 9 years ago  |  last reply 7 years ago

### High Current measurement using Arduino?

I need to measure Current from a welding machine to make a alarm if it goes down below some level for ensuring better quality.The current normally set is of the order of 200A max with around 100V DC.Not sure if i could use some clamp-on meters and decode the values. Shunt resistors may be a better option. But to make a signal conditioner to convert the ma output will be a problem i guess..is there something i can do with Arduino.. any ideas guys....?

Asked by chuppandi 6 years ago  |  last reply 6 years ago

### how to measure inductance using a bridge?

My LCR meter can only read inductances of mH to a few Henries. I need to make a 470uH inductor, since in my place inductors are not so common. How can i measure inductances at microhenries if my LCR meter's reading capability only ranges from millihenries to henries? Someone told me to use bridges like wheatstone bridge or maxwell bridge to have an accurate reading, but i don't know how to do it. Can you suggest any reference? I prefer doing wheatstone. Thank you in advance :)

Asked by codestroy7 7 years ago  |  last reply 7 years ago

### Measure RPM and MPH on motorcylce with Arduino

Hi all, I have an idea for an Arduino based instrument cluster for my cafe racer (1980 xs400). My question is what kind of rotary encoder I should use to measure the rotation from the cables coming from the engine block and front wheel that went to the original cluster (shown in pictures). I want something that won't break at higher RPMs and is more or less water proof. I have an idea of how to code this on the software level as well, but I'm not to experienced with C/C++ so any help there would also be appreciated. The end goal for this part of the cluster is to output the RPM and MPH to respective WS2812B 5050 LED strips, and possibly a small oLED later down the line. If something could be made more clear on this post let me know and I'll try to elaborate. Thanks again

Asked by AedanGraves 6 days ago  |  last reply 5 days ago

### Circuit to measure internal resistance of a battery?

Asked by Farawayman 4 years ago  |  last reply 4 years ago

### Having trouble measuring voltage with arduino.

Asked by faraz ahmed khan 1 year ago  |  last reply 12 months ago

I was thinking about a laser cut ruler. Is it really pointless? It will be made out of blue light-gathering acrylic. I was just wandering if it was going to be useless...

Asked by knektek 8 years ago  |  last reply 8 years ago

### Export Google SketchUp as just the faces and measurements?

I made a simple chair in Google SkecthUp and wanted to make it out of cardboard(lot of time on my hands). I was wondering if their was a simple way to export all the faces and measurements in the .skp file?

Asked by Chromatica 8 years ago  |  last reply 8 years ago

### HELP measure resonant frequency on induction heating. ? Answered

Dear  All..... In this circuit and formula  on (GOOGLE). Please could you help me to know 3 questions: -How  I can measure resonant frequency  of this circuit, because it has   2 L and 2 C on this circuit?. - where I  must to put the probes in this circuit for measures frequency? - If I want to used less power(less heating) I must change L  or C  or both?  Thank you so much in advance  for your time.

Asked by lam 6 years ago  |  last reply 6 years ago

### How to measure the distance up to 200m (with arduino)??? Answered

Hi ... how would you measure the distance up to 200m using the arduino ??? 1. What would you use ??? 2. Is it possible to modify the PING))) sensor to be able to measure such distance ??? 3. Do you think, that this radar kit www.hobbytron.com/r-sg7.html could me modified to do the job ??? There is a 'pdf' file for more information. 4. Or would you use laser - how ??? Thank you in advance for you answers/suggestions. zholy

Asked by zholy 9 years ago  |  last reply 6 years ago

### Push button duration measurement inside FPGA

Hello, I need to measure the time between press and release a button in an FPGA (time between rising and faling edge) and dispaly the time result the seven segment dispaly of the FPGA , I do somethink but it doesn t work , can any one help please or give a program ,????

Posted by mirabelle275 11 days ago

### How to measure max output current of transformer ?

Asked by Rendydevara 7 years ago  |  last reply 7 years ago

### Having trouble measuring accurate voltage with arduino.

Asked by faraz ahmed khan 1 year ago  |  last reply 1 year ago

### How can I measure grams without a scale?

For those who have done the measurements for thermite..  I know you're supposed to measure the iron oxide and AL powder by weight but does anyone have the measurements like in teaspoons or whatever because I dont have a scale.. Thanks in advance for your answers.

Asked by jules15 8 years ago  |  last reply 8 years ago

### how would you measure the force that something exerts?

Asked by kazpro 7 years ago  |  last reply 5 years ago

### How Do I Measure Coefficient of Productivity (COP) ? Answered

I just recently ran into this term and cant find the definition on the internet.  Can some one please explain to me what Coefficient of Productivity is and how to measure it? Thanks, Kalrag

Asked by Kalrag 8 years ago  |  last reply 8 years ago

### How to measure pre-shirred material for a summer dress?

I am new to making clothes and am self taught on my sewing machine. I bought this really cute cherry pre-shirred material, and am trying to figure out how to measure it to fit my body right. Is there a special way I need to do this, or is the answer right under my nose and its passing me by? Any adivce would be greatly appriciate. So, again, my question is, How to I measure the pre-shirred material to make my summer dress?