AVR-Chat

Are the bottles transparent?  If so, you could use a laser and photo diodes; the wavelengths absorbed could even tell you what was in the bottle.

Regards,

Tim Gilbert
JEM Innovation Inc.
303-926-9053 (office)
303-437-4342 (cell)
720-890-8582 (fax)
www.jeminnovation.com
www.pdksolutions.com

  ----- Original Message ----- 
  From: Ken Holt 
  To: AVR-Chat@yahoogroups.com 
  Sent: Tuesday, January 13, 2009 7:20 PM
  Subject: Re: [AVR-Chat] Liquid level measurement


  I have used capacitive sensing successfully on a 4' high
  fiberglass tank, measuring the height of the water inside
  to within and inch. I used only one metal plate; the water
  inside was a good enough ground plate.

  Enki wrote:
  >
  >
  > I need to measure the liquid level inside a transparent plastic
  > bottle. I need to know when the liquid is below half bottle height and
  > when the bottle is almost empty. Just two steps.
  > The plastic bottle measures 12cm high x 8cm x 3cm.
  > I'm not allowed to insert any probe in the bottle.
  > There are four bottles side by side.
  >
  > I was thinking on metal plates mounted on each side of each bottle
  > and using the capacitance method.
  >
  > Or a B&W video camera and some processing. I could generate four
  > sample windows on each video line and integrate the samples. The four
  > integrated signals would represent the liquid level on each bottle.
  > An ATMEGA48 would do the level measurement with four ADCs.
  >
  > Comments, please.
  >
  > Thanks,
  > Mark Jordan
  >
  > 



   

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