Method of determining the quantity of radiation absorbed by a radiation sensor

US6840674B2 · kind B2 · utility

Assignee

• KONINKLIJKE PHILIPS ELECTRONICS NV · NL

Inventors

• Ralf Schmidt · Nuremberg, DE
• Kai Eck · Aachen, DE

Key dates

• Filing date: Mar 20, 2002
• Grant date: Jan 11, 2005
• Expiry date: Mar 20, 2022

Classification

• Technology area (CPC G): Physics
• CPC primary: G01T1/40
• WIPO field: Environmental technology
• WIPO sector: Chemistry

Abstract

The invention relates to a method for the calibration of a radiation sensor, in which method a first calibration takes place with external radiation x and an internal signal s of the radiation sensor, and in which later calibrations are carried out exclusively with the internal signal. This enables the calculation of an approximate value x*(t) for the quantity of radiation x(t) absorbed in a radiation sensor (10) while taking into account a behavior of the radiation sensor that changes in time. First the primary characteristic ft1(x) is measured at a first instant t1; this characteristic describes the dependency of an output signal o on the absorbed quantity of radiation x. At the same time the secondary characteristic gt2(s) is measured, which characteristic describes the dependency of the output signal o on an internal signal s. The signals s and x should together form an intermediate signal w that is further processed with a function D(w,t) that varies in time in order to form the output signal o. The secondary characteristic is measured again at a later instant t3 after the occurrence of aging; this measurement can be performed without utilizing (X) radiation. The calculation o…