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. 17, 1990
Filed:
Apr. 10, 1989
Richard C Loshbough, Westerville, OH (US);
Toledo Scale Corp., , OH (US);
Abstract
Weighing apparatus including variable capacitance load sensing means, a capacitance detection circuit, an analog to digital convertor and microcomputer control means is automatically verified for accurate operation. The capacitance detection circuit is provided with a computer controlled verification switch by which the value of a parameter, such as resistance in an attenuation circuit, can be changed. Automatic verification of correct operation is obtained by periodically, with no weight on the scale, obtaining a first weight reading, operating the verification switch to change the parameter and obtaining a second weight reading. The difference between the two readings is a verification value and is compared to a stored verification value obtained in the same manner during calibration and stored for later use. If the difference between the obtained and stored verification values exceeds an allowable limit, the scale may be disabled from further weighing.