Pyrometer electromagnetic radiation measuring device

US5640015A · kind A · utility

Assignee

• Raytek Sensorik GmbH · DE

Inventors

• Ulrich Kienitz · Berlin, DE
• Thomas Heinke · Santa Cruz, US
• Uwe Klonowski · Berlin, DE
• Peter Preuss · Munich, DE
• Holger Sandring · Berlin, DE
• Volker Schmidt · Lexington, US

Key dates

• Filing date: Oct 23, 1995
• Grant date: Jun 17, 1997
• Expiry date: Oct 23, 2015

Classification

• Technology area (CPC G): Physics
• CPC primary: G01J5/52
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A pyrometer for measuring the electromagnetic radiation emitted by an object comprises a first detector to which the radiation is delivered through an optical system as well as a second detector to which the radiation emanating from a reference element is delivered through the same optical system. The temperature of the reference element is monitored and a rotary optical modulator periodically enables and disables the delivery of radiation to the detectors. The output signals from the two detectors are processed to determine the difference therebetween. The sensed temperature of the reference element is taken into account as a part of determining the difference between the two detector output signals. In this way it is possible for the characteristic radiation of the optical system largely to be suppressed. The optical modulator comprises a semi-circular disk having a polyethylene terephthalate substrate coated on each side with metal. The disk is rotated through 180.degree. increments by a stepping motor such that, in one angular position, the disk permits reception by the two detectors of radiation from the optical system and, in the other angular position, the disk prevents rece…