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. 07, 2013
Filed:
Dec. 25, 2007
Mitsuaki Koyama, Sayama, JP;
Mitsuaki Koyama, Sayama, JP;
Nihon Dempa Kogyo Co., Ltd, Tokyo, JP;
Abstract
A sensing instrument using a piezoelectric resonator changes natural frequency when coming into contact with a liquid to adsorb a substance to be sensed in the liquid. The sensing instrument includes an oscillator circuit supplying a piezoelectric resonator with oscillation driving power for oscillating the piezoelectric resonator so as to set a driving current to 0.3 mA or less. A measuring unit measures a concentration of the substance to be sensed based on an oscillation output of the oscillator circuit. Self-heating of the piezoelectric resonator is suppressed. Consequently, a change of the oscillation frequency of the piezoelectric oscillator is suppressed, which as a result enables accurate detection of a variation of the frequency due to the adsorption of the substance to be sensed.