I am using this pair of photo transistor and photo diode..i am confused about biading ckt of photo transistor..light emmited by LED wii pass through turbid solution and change in the intensity is detected by photo transistor..this is how it should work ..please help mee..
Hil All
The photo trasistor is a infrared Type(receiver).To maximaze sensitivity you should use an infrared diode instead of a white led.
Take a look in the figures for the white led(pag 6) and the photo transistor(pag3) you will see the peak emmission is at about 460nm for the white led but the peak sensitivity for the photo transistor is at 960nm.