Patent ID: 6222176
Filing Date: 2001-04-24
Classification: G01N

Abstract:
An auto-ranging densitometer for determining the density of a test sample, said densitometer comprising:a photodetector that generates an electrical signal in response and proportional to incident light;an amplifier circuit adapted to produce an output signal proportional to the electrical signal, the amplifier circuit having multiple gains that successively increase;an analog to digital converter adapted to convert the output signal of the amplifier circuit to digital format;a gain select logic circuit to output a gain code to select the amplifier gain; anda density signal generator circuit including two LUTs, wherein the gain code is used to address the LUTs one of the LUTs is adapted to receive the out put of the analog to digital converter and produce an output density scaled to include only low order bits; and the other LUT is adapted to receive the gain code and produce a output density scaled to include only high order bits, and a concatenation adder of the outputs of the two LUTs to produce a summation density signal.