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Smoke detection sensor


Hi there

I have been wanting to detect smoke ( from cooking of food) in my kitchen. I was looking at sensing mechanisms used in conventional smoke alarms and found that one is based on ionization and other based on photoelectric phenonmenon. However, I couldn't find any commercially available sensors I could buy.

Does anybody know about this? Or have a better idea



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A complete alarm probably won't cost much more than the sensor alone (assuming you could source one).
But you need to change your cooking style if the food is giving off smoke :D.


Ah ok! I will go for the smoke alarm then. Gonna see if I can hack in to the sensing part.

I am a Pakistani . Our food( Indian/Pakistani) isn't 'ready' until the kitchen is all smoked up lol! :)


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There are several different classes of smoke/fire alarm sensors.

Ones for normal rooms will be set of very easily by cooking fumes, to the point of serious annoyance!

Types designed for such as kitchens generally use either simple temperature detection above normal occupancy levels rather than smoke detection, or "rate or rise" of air temperature.

The Texecom ones are good examples - they do four versions, a conventional smoke detect, a rate-of-rise and two fixed temperature ones.
This series just need 12V power and the alarm is from a separate "floating" contact.

Edit - correcting a typo.
Last edited:


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If you are trying to detect smoke as an experiment (and NOT to protect your house), you can have fun with this circuit.

A simple smoke or particulate sensor can be made from a pair of simple Red OR Green OR Blue LEDs (do not use white LEDs).
One LED is simply wired with a resistor in series to give off Light. The other is placed 90° to the first and is wired like a photoDiode and used as a sensor.

Put each LEd in a Shroud - like an old 35mm film canister, a prescription pill bottle painted black or the shaft of a black-body from a bic (or similar) ball point pen. Then position the, at 90° to each other so when the red light of the LED hits the smoke, the smoke can be be reflected into the second LEd. It is best to use the T1 3/4 (5mm bullet) indicator style LEDs.

Something like the following for a very basic proof of concept.

Then you can move on to use a modulated LED light source (e.g. 38kHz) and a filtered detector to cancel out ambient light.

Have fun. Don't use this circuit as a life-saving device. Also, it doesn't work well for black smoke (soot/lamp black) but works well on smoke from wood or paper fires - including cigarettes.



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Interesting Gophert.


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