Signal processing for optical computing system
The present subject matter relates to methods of high-speed analysis of product samples during production of the product. Light is directed to a portion of a product under analysis and reflected from or transmitted through the product toward optical detectors. Signals from the optical detectors are compared to determine characteristics of the product under analysis. Temperature within the monitoring system may be monitored in order to provide compensation for the signals produced by the optical detectors. The products under analysis may be stationary, moved by an inspection point by conveyor or other means, or may be contained within a container, the container including a window portion through which the product illuminating light may pass.
1. A method for high-speed analysis of product samples during product processing, comprising:
providing an illumination source;
illuminating with a portion of the light from the illuminating source at least a portion of a product with light at an inspection point;
providing first and second light sensitive detectors, the detectors producing output signals based on received light;
directing a portion of the light from the illuminated product portion toward the first and second light sensitive detectors, the light from the illuminated product portion carrying information about the product portion;
directing at least a portion of the light from the illumination source toward the first and second light sensitive detectors as a reference light;
providing a temperature sensor in proximity to the first and second light sensitive detectors, the temperature sensor producing an output signal based on temperature;
compensating the output signals produced by the first and second detectors based on the temperature output signal; and
analyzing the compensated output signals produced by the first and second light sensitive detectors to determine temperature compensated illuminated product portion information.
2. The method of claim 1 , wherein the product is at least one of a pharmaceutical tablet, a pharmaceutical powder, a food material, a chemical, a liquid, a gas, an emulsion, a solution, or a mixture thereof.
3. The method of claim 1 , wherein the product is a powder mixture in a closed container, the container being at least partially transparent to the illuminating light.
4. The method of claim 1 , further comprising:
moving the product past the inspection point.
5. The method of claim 1 , wherein directing light from the product portion comprises directing light reflected from the product portion.
6. The method of claim 1 , wherein directing light from the product portion comprises directing light transmitted through the product portion.
7. The method of claim 1 , wherein illuminating comprises illuminating the product with a spectral-specific light.
8. The method of claim 7 , further comprising:
illuminating the product through an optic window, the optic window being configured to focus the spectral-specific light onto a product portion at the inspection point.
9. The method of claim 1 , wherein the product comprises a plurality of discrete portions.
10. The method of claim 9 , wherein the plurality of discrete portions are disposed in closed containers, the containers at least partially transparent to the spectral-specific light.