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:
Apr. 23, 2002
Filed:
Aug. 26, 1999
Masumi Sakai, Kyoto, JP;
Kazuo Nagasawa, Kyoto, JP;
Shimadzu Corporation, Kyoto, JP;
Abstract
For calibrating a spectrophotometer having a monochromator with a rotary mechanism to rotate a diffraction grating for producing a monochromatic beam of light of a specified target wavelength, transmission errors by the rotary mechanism are preliminarily measured to obtain an error curve having peaks corresponding to feed angles. A smallest angular interval, greater than an allowable limit, between a pair of feed angles corresponding to a mutually adjacent pair of peaks in the error curve is selected. One or more lamps emitting bright lines with wavelength interval which corresponds to motion of the rotary mechanism by less than one half of the selected smallest angular interval are used as a light source. Control values to be supplied to the rotary mechanism for obtaining monochromatic beams of light from the bright lines emitted from the selected lamps are determined by measurements. A calibration table, from which a required control value corresponding to a specified wavelength value can be retrieved, is produced from these control values and wavelength values of the bright lines and is stored in a memory device.