Photo-detector to measure signal at 1 - 2 cm
Photo-detector to measure signal at 1 - 2 cm
(OP)
Can comebody suggest a good photodetector that will provide a signal when mettering at a 1 to 2 cm distance from a wet surface? The idea is to measure 1 for the existence of calf skin, and zero when there is no skin. ( I am designing a skin meter).
Thanks for the advise.
Thanks for the advise.





RE: Photo-detector to measure signal at 1 - 2 cm
<nbucska@pcperipherals.com>
RE: Photo-detector to measure signal at 1 - 2 cm
The proble is that most of the photo-detector that I am familiar with, have a narrow surface to surface distance.
RE: Photo-detector to measure signal at 1 - 2 cm
Make an IR radiator (LED, 40 kHz osc. focusing optics ) to send a beam at 45 deg. Use the detector with narrow optics.
The 40 KHz source may be either an LC osc. or XTAL -- e.g. 1 MHz with divider.
<nbucska@pcperipherals.com>
RE: Photo-detector to measure signal at 1 - 2 cm
RE: Photo-detector to measure signal at 1 - 2 cm
You can scan e.g. with rotating mirror or servoed mirror.
<nbucska@pcperipherals.com>