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Electronics => Electronics => Topic started by: aruna1 on February 01, 2009, 01:36:51 AM

Title: ambient IR help
Post by: aruna1 on February 01, 2009, 01:36:51 AM

hello I was abl to make a fire detector sing photo diode(with IR filter) and a OP amp.now i have a problem.how to avoide errors cause due to ambient IR? I tried to cover the sensor but it didnt do any good.then i reduse sensitivity but it also reduce the sensitivity to flame.so any help would be great.
thanks

Title: Re: ambient IR help
Post by: Soeren on February 01, 2009, 01:46:39 PM

Hi,


You really should consider a pyroelectric sensor - it is (nearly) blind to ambient.

With a photo diode you'll have loads of trouble, since the diode cannot differentiate flames from ambient.

Title: Re: ambient IR help
Post by: aruna1 on February 01, 2009, 02:03:36 PM

but problem is pyroelectric sensors will begin to detect humans if there is a way to avoid t then i'll move to pyroelectric ???

Title: Re: ambient IR help
Post by: Soeren on February 01, 2009, 04:49:38 PM

http://www.kube.ch/downloads/pdf/kube_pyro_ar172.pdf (http://www.kube.ch/downloads/pdf/kube_pyro_ar172.pdf)

Also try using Google to see what other has done previously.

Title: Re: ambient IR help
Post by: aruna1 on February 01, 2009, 06:50:25 PM

cool