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:
Jul. 28, 2009
Filed:
Dec. 13, 2004
Sadao Omata, Tokyo, JP;
Yoshinobu Murayama, Tokyo, JP;
Katsuhito Honda, Fukushima, JP;
Nihon University, Tokyo, JP;
Abstract
In a hardness measurement system, selecting an operating frequency is facilitated by using a phase shift circuit. A hardness sensor is connected to an operating frequency selection apparatus and in a free end state the amplitude versus frequency characteristic is acquired, and the frequency and the phase of the peaks are measured and acquired as the free end characteristic. Next, the hardness sensor is placed into contact with a first test piece, and the frequency and the phase that change for the peaks are measured and acquired as the first characteristic. The same procedure is performed for a second test piece that is harder than the first test piece to yield the second characteristic. Based on these characteristics and a predetermined selection criterion a peak suitable for hardness measurement is selected and the operating frequency is set from the frequency of the peak.