The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 22, 1990
Filed:
Feb. 17, 1987
John Howarth, Monte Sereno, CA (US);
Leonard M Anderson, San Jose, CA (US);
Measurex Corporation, Cupertino, CA (US);
Abstract
An infrared paper web moisture sensor is described which comprises a source of infrared radiation for directing an infrared beam through the web and an infrared detecting unit disposed on the opposite side of the web from the infrared source. In one embodiment, the infrared detecting unit measures the transmission of the infrared beam through the web at three separate wavelength regions of the infrared spectrum, one of which is sensitive to web temperature. In a second embodiment, the infrared detecting unit measures the transmission of the infrared beam through the web at two separate wavelength regions of the infrared spectrum, one of which is insensitive to web temperature. For each embodiment, signals are developed indicative of the transmission of infrared through the web in each of these regions, digitized, and fed to the process control computer for the paper mill. The computer combines the values of the digitized signals, via an empirically derived equation, to produce a value indicative of the percentage of moisture in the web. The process control computer utilizes this result of control devices which selectively add moisture to portions of the web or selectively dry portions of the web to thereby produce a web having a uniform moisture content.