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:
Jun. 05, 1984
Filed:
Mar. 06, 1981
Michael A Ford, Buckinghamshire, GB;
Perkin-Elmer Limited, Buckinghamshire, GB;
Abstract
The accuracy of the ratio between two time-varying quantities represented by electrical signals, such as the sample transmission (or absorption) signal and the reference signal in a double-beam, ratio-recording, infrared spectrophotometer, is impaired if the electrical signals are subject to inconstant phase shifts. The present invention counteracts the effect of phase shift variations, whatever their origin, by alternately reversing the order in which an elemental component of one quantity is made to occur with respect to an elemental component of the other quantity so that the said effect reverses in sign when the order is reversed and substantially cancels out when the respective elemental portions are combined to form the numerator and the denominator of the ratio. The invention is particularly described with reference to a spectrophotometer of the type referred to.