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Sensors, Actuators, and Robotics » Sensor Suggestions?

September 27, 2012
by lucimur
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Hi All,

I have an application in which I would like to detect a threshold change in pressure being generated by compressed air being shot out of an small hole. The sensor should act as a momentary switch that provides a rising edge and a falling edge signal as the air pressure is momentarily increased and then decreased.

Do you have any suggestions for a sensor that I could use with my NerdKit for such an applications?

Thanks!

September 27, 2012
by Ralphxyz
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lucimur, do you need to read an actual pressure change or just sense the change?

If you "need" to read moving air pressure you will need some sort of pitot tube sensor and then a pressure sensor and probable an amplifier.

If all you need to know is that a steady air stream has stopped than you could just have a ball switch that was blowing in the wind and then would drop when the air was no longer blowing.

Ralph

September 27, 2012
by lucimur
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Hi Ralph,

I only need to sense the change (I expect this to take the form of a sharp "spike" in pressure that lasts for a fraction of a second).

Thanks,

Murray

September 27, 2012
by Ralphxyz
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Hi Murray, so you are looking for an increase in pressure?

That makes it a little harder, the ball switch I could picture working for a loss of pressure.

I'll have to think a little more about how to sense an increase in pressure.

Well of course the pitot tube will do that.

I am really tempted to get one of these just to play around with.

Ralph

September 27, 2012
by lucimur
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Thanks, Ralph.

I'm tempted to try one of these: http://canada.newark.com/jsp/search/productdetail.jsp?SKU=03J5401

What do you think, given the description of my application?

Murray

September 28, 2012
by Ralphxyz
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The one I had said I might get to play around with uses the MPXV7002 series piezoresistive transducer. It is in the same family as the one you are looking at except it is a whole kit with the pitot tube and a servo cable. I would assume the servo cable is to hook up to a mcu.

If you purchase just the transducer your would still need a pitot tube.

Ralph

September 29, 2012
by Ralphxyz
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I bought the Airspeed Kit it will be a while before I have a need for it on a air plane or copter but I know eventually I will need it so figured I can play with it now using my vacuum cleaner to get the air moving. With the vacuum cleaner I should be able to see air speed and vacuum.

I wonder how it will do as a wind speed indicator? For a weather station.

Ralph

September 29, 2012
by JimFrederickson
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Ralph that "http://store.diydrones.com", where you got your Airspeed Sensor, is a pretty cool place!

Lots of interesting products there...

September 30, 2012
by Ralphxyz
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Yeah Jim, it is a very interesting site. I am going to go back for more.

Ralph

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