REFLECTOMETRY SYSTEM WITH COMPENSATION FOR SPECIMEN HOLDER TOPOGRAPHY AND WITH LOCK-REJECTION OF SYSTEM NOISE

摘要

A self-contained system uses light reflectivity to examine intensity of a dyed spot on a device membrane surrounded by background area to discern information about the specimen that produced the spot. In a preferred embodiment, a master clock alternatively drives one LED focussed upon the spot center, and then drives two LEDS focused on the background area. Light reflected from the spot and background is detected by preferably two photodetectors ("PDs") spaced-apart a multiple of 90° azimuthal.