[Solved] Infrasound detector info needed

[Rafa]

Dear all, some ideias are welcome on this matter;

Does someone has a project of infrasound detector? Cheap please...
There is one on the March 2013, Silicon Chip Magazine, but i can't find it anyway.

Thanks a lot!

[solutions]

What do you use it for?

[Rafa]

Hmm hehehe!! to detect infrasound waves!! 

Well, some ideas...
I'll see the behavior on wind turbine generator camp, if there are these waves. It has been said that people get sick with them.
After that i'll try on landings and take off on airport. And then to see if my infra waves generator is near to work as expected...
But i need the detector first.

So if possible, will to differentiate the signal of them all in time domain and intensity.
For those i need some small portable device, maybe as the project on the magazine i told before.
Need to see it to know if it fits on my needs...

For the last, i'll try to monitor (if possible) the relation on atmosphere infra waves and the approach of storms.
I read there should be one correlation on it. To that i know there is the need of such a big sensor arrays, i just
found one project with optical fiber 90 m long attached on a infrared spectrometer. (out of my range)
But there are some design out there with piezo transducers for that same matter.

The idea should go through these:
infra waves => sensors => pre amplifier => pic=> usb => pc => heat map C# program

Thanks, any help is appreciated!

[Catcatcat]

When, in the USSR, tests were made to establish directional generator infrasonic vibrations. It seems to have created the device allows you to create a directional beam. But the generator is an option police whistle. And the dimensions of a small room. A detector, I think it would be an interesting thing, the registration of sound waves in the 1-2 Hz. I apologize for my English, all claims to Google.

[mare69]

Just an idea. I made matrix of 100 (10x10) pressure sensors with 1mbar full scale. When I yell at them, I can see profile of the sound. The sensors were connected to the PC and I wrote small opneGL application to visualise the responses in real time. The sensors resolution was 16 bits with about 2-3 bits noise. With 12 bit, the resolution of 1 mbar sensor is 0,25 uBar (microbar). Is this enough for sensing infra sounds?

[Rafa]

Please, we don't shall go in to a nuclear precision here, as i see discussion on other topics.
I'm just trying to learn about it and see if something if feasible to be done.
All info i have is from read papers...

Catcatcat:
i don't belive it needs to be so large device, cause it's reported that big fans or wind blower can do the trick.
And the beam question put me in doubt, because these waves goes very far, no direction just propagation, 
and i don't see how to put them in a single beam. And it's not the intention here, no gun...

mare69:
the numbers i have till now are: 0.01 - 20 Hz and 0.05dB. So it looks enough, but these microbars sensors have
the problem of fluctuations of wind speed changes, and so they need some dificult encapsulation. And your yelling
has a different compoud of waves, there would be need some filters for wery low pass band.

Thanks.

[Catcatcat]

Infra low vibrations are sound waves that have a sufficient length, it may be a variant, the pressure measured by two sensors spaced a predetermined distance?
_{An apology for the English language}

[LithiumOverdosE]

It may be a crazy idea but perhaps you could use modified ESL design?

If the diaphragm is light enough (thin PET or Mylar, coated with layer of graphite spray paint) and large enough you should be able to measure change in capacitance between moving diaphragm and grid(s).  

[Rafa]

No it's not crazy, but it gives me two problems, as it needs to be out of weather and will be to big to carry.
I've found something about it before, but there are little designs out there, and i'm searching them.

Possible there will be less precision, but to begin to study it, i need to take it on the right places first,
were these signals waves are.

When i find these designs, if i find, will put them here.
Thanks!

[LithiumOverdosE]

No it's not crazy, but it gives me two problems, as it needs to be out of weather and will be to big to carry.

Yes, weather could be a bit of a problem.

As for portability, perhaps you could make foldable design with additional, guitar-like tensioners to adjust tension of diaphragm when you're preparing it for deployment.

You could also consider using metallic anti-mosquito net for grids due to their low weight. Or even plastic ones sprayed with graphite. And then use tensioners to adjust tension when needed.


The way I see it, the design would then be very light and could be folded for transport, and surface irregularities would probably be flattened when you apply appropriate tension.

[Ichan]

This one seems interesting: The Inexpensive Infrasound Monitor Project

-ichan

[Rafa]

Lithium: i got your idea, will wait little more to see what the other guys talk about before give some try.

Ichan: yes!! I'm in the middle of the links, found it 2 days ago, lots of info. But no schematic yet.
It's not that expensive, but the fee and the post bring it to far for me...

Cheers!

[solutions]

Please, we don't shall go in to a nuclear precision here, as i see discussion on other topics.
I'm just trying to learn about it and see if something if feasible to be done.
All info i have is from read papers...

And you're not sharing these papers with your friends here, because....?

[Rafa]

Cause... no one has asked before!!! 

Many of them I discarded, so isn't much, and follow Ichan's link, there is a lot info.
I'm still reading...
Enjoy!

Posted on: September 13, 2013, 02:40:44 14:40 - Automerged
Ok, i'm still searching, nobody anymore?

I found this yesterday and it's the most 'compact' design till now...
But not much info, just one idea.

Posted on: September 21, 2013, 01:59:47 13:59 - Automerged
This is one good instrumentation book and has a good ideia on design that could be used for infra.
But i don't know how determine the resonance frequencies to use it.
It's hard to find something realy usefull for this matter, and the replies just stopped...

I searched for the Silicon Chip Magazine and found a lot of projects, i don't have interest on them right now, but could be usefull for others.
It's a big rar file, can i post it here or do i need to start other topic? Do i need to split it in several parts? It's 170mb big.

I don't want to be punished by the admin and i've seen they are angry these days...

Cheers

Posted on: October 03, 2013, 11:35:26 23:35 - Automerged
Well i don't know how but the above should be a pdf file and it wasn't so. Now i've fixed it.
Sorry for those who downloaded it and could not open it. 

No news for help me on infra? Thanks
Cheers!

Posted on: October 14, 2013, 07:41:11 19:41 - Automerged
Long time searching and sniffing around...
Enjoy!

[bbarney]

Check march 2014 edition of EPE mag - it's probably a re-print of the older silicon chip article

[Rafa]

Exactly, this is the file I add via the posted link...