Smoke Sensor

[hendrachubby]

Anyone can recommend me a sensor to detect smoke intensity ?

[galannthegreat]

If the idea of using a smoke detector is in your mind, don't do it, it has a radioactive element inside of it (Americium). Now my suggestion would be looking at optical methods, such as this http://en.wikipedia.org/wiki/Smoke_detector.

Hope this helps!

[Admin]

Hack a smoke alarm: Wire the buzzer pin to your microcontroller. Done.

(or any other pin that does binary and not PWM, just use your multimeter to check)

[hendrachubby]

can i use combination of photodiode and LED ?

[Admin]

can i use combination of photodiode and LED ?

tell us more about the environment, distance away, type of smoke, etc

[HDL_CinC_Dragon]

Where there is smoke their is heat. What temperature range will your circuit be exposed to?

[hendrachubby]

i want to measure cigarette smoke thickness, because i got a research about thermoforesist filter..so i must measure the smoke intensity before and after the filter...i've tried using combination of led and photodiode, but the voltage deviation is small...any idea ?

[awally88]

Try using an Op Amp to amplify the voltage that you get from the photoresitor.

[Soeren]

Hi,

You could buy a cheap fire alarm (make sure it's got an optical detector - the package will tell, but they are the usual type sold cheap - $4 to $8 should get you one), it has got a matched pair of IR LED and IR photo diode that you can harvest and you'll see how it is mounted.

Here is one I dismantled to use the detector for automatic opening of windows on "poker nights"

http://That.Homepage.dk/Img/Optical_Smoke_Detector.jpg

You need to mount the pair in a way so they cannot see each other, but just the light reflected from the smoke particles - use baffles for that.

http://That.Homepage.dk/Img/Smoke_Intensity.png

Make sure the "funnel" covers the entire output of the filter (turn it upside down for the input to the filter).

You'll need to calibrate the outputs to get reliable results of course.

[hendrachubby]

Okay, so fire alarm use combination of IR led and IR photodiode...humm that's very helpfull, because i don't know fire alarm use that..thx