Method and apparatus for determining a substance using THz radiation

US9354168B2 · kind B2 · utility

Assignee

• Fraunhofer-Gesellschaft zur förderung der angewandten Forschung e.V. · DE

Inventors

• Bernd Sartorius · Berlin, DE
• Helmut Roehle · Berlin, DE

Key dates

• Filing date: Jul 31, 2012
• Grant date: May 31, 2016
• Expiry date: May 3, 2033

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2021/4153
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The invention relates to a method for determining a liquid in a closed container using THz radiation, in which a first and a second measurement are carried out, wherein the THz radiation is emitted in the direction of the liquid for measuring properties of the liquid, and a portion of the THz radiation coming from the direction of the liquid is detected. In the proposed method, the closed container contains, in addition to the liquid, a gas, wherein a wall of the container is transmissive for THz radiation and wherein the detected portion of the THz radiation in the first measurement is reflected at a boundary surface between the wall and the gas or a pocket containing the gas, and the second measurement is reflected at a boundary surface between the wall and the liquid. The first measurement thus serves as a reference measurement for capturing disturbing losses in the THz beam path and for determining influences of the wall on a measurement result for the second measurement. The invention further relates to an arrangement suitable for carrying out this method.