I'm attempting to create a 'chamber' that holds a custom made reflective optical sensor to sense the presence of smoke inside. My current attempts include a IR LED and a photo-transistor that has a peak sensitivity is that of my LED's wavelength. However, i can't seem to get the set up to work properly. I know that they work together because when i have them facing each other i can get a analog reading from the transistor when connected as the following circuit.
However, once i attempt to create some sort of DIY chamber to test this using cardboard, to look like the following it just doesn't seem to pick up the light that reflects from the smoke.
The following are the datasheets of the IR LED and the photo-transistor, please let me know if you feel i have the incorrect hardware for the job. I have got a photo-diode on order to test this out in case the transistor is the issue.
IR LED - http://www.farnell.com/datasheets/1683593.pdf
Photo-transistor - http://www.farnell.com/datasheets/1683591.pdf
However, once i attempt to create some sort of DIY chamber to test this using cardboard, to look like the following it just doesn't seem to pick up the light that reflects from the smoke.
The following are the datasheets of the IR LED and the photo-transistor, please let me know if you feel i have the incorrect hardware for the job. I have got a photo-diode on order to test this out in case the transistor is the issue.
IR LED - http://www.farnell.com/datasheets/1683593.pdf
Photo-transistor - http://www.farnell.com/datasheets/1683591.pdf