Light source pulsed with irregular pulse sequence in analog photometric signal evaluation for a test carrier analysis system

US5463467A · kind A · utility

Assignee

• Boehringer Mannheim GmbH · DE

Inventors

• Edgar Baumann · Mannheim, DE
• Wolfgang Obermeier · Heidelberg, DE
• Karl Werner · Stuvsta-Snättringe, SE

Key dates

• Filing date: Jun 27, 1994
• Grant date: Oct 31, 1995
• Expiry date: Jun 27, 2014

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2201/0699
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Method of detecting and evaluating analog photometric signals in a test carrier analysis system, and apparatus for carrying out the method. The test field of a test carrier is irradiated by a light source clocked in light-dark phases. The reflected light is detected by a measurement receiver over a measurement period having several light-dark phases, and integrated. An effective suppression of stray and secondary light, which permits measurement even without the hitherto conventional shielding from ambient light, is achieved by a method in which the sequence of the light and dark phases integrated over the measurement period is irregular in such a way that the Fourier-transformed frequency spectrum includes a large number of different frequencies. Each individual frequency therefore makes only a small contribution to the measurement result.