ambient IR help

[aruna1]

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

[Soeren]

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.

[aruna1]

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

[Soeren]

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

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

[aruna1]

cool