Fire & Ambient IR: Is there a Difference?

[aruna1]

hello
can someone tell me are ambient IR and IR in candle fire has different wave lengths?
I'm trying to make a flame detector,so if there is different wave lengths i can use a filter circuit to filter only fire's IR signal.
Thanks

 

[Mapes]

I think your best bet is to look at wavelengths around 1-2 um. According to Incropera and DeWitt's Fundamentals of Heat and Mass Transfer there's very little emission under 2 um for bodies at 300 K.

 

[aruna1]

I think your best bet is to look at wavelengths around 1-2 um. According to Incropera and DeWitt's Fundamentals of Heat and Mass Transfer there's very little emission under 2 um for bodies at 300 K.

well sir does candel fire emits IR around 1-2um? I'm not familier with physics laws you mentioned.

 

[Mapes]

All materials emit all wavelengths, but there's a characteristic peak that's a function of temperature alone. For room temperature objects, it looks like the peak is around 10 um. For a candle flame, 1-4 um.

 

[uart]

well sir does candel fire emits IR around 1-2um? I'm not familier with physics laws you mentioned.

Yes, with a typical candle color temperature of about 2000k, by my calculations 2um should be reasonably close to the peak wavelength emitted.

 

[aruna1]

All materials emit all wavelengths, but there's a characteristic peak that's a function of temperature alone. For room temperature objects, it looks like the peak is around 10 um. For a candle flame, 1-4 um.

Yes, with a typical candle color temperature of about 2000k, by my calculations 2um should be reasonably close to the peak wavelength emitted.

thankyou very much both of you sirs