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:
Dec. 27, 2016
Filed:
Jun. 04, 2012
Hidetsugu Tanoue, Tokyo, JP;
Kazuhiro Tanaka, Tokyo, JP;
Hidetsugu Tanoue, Tokyo, JP;
Kazuhiro Tanaka, Tokyo, JP;
Hitachi High-Technologies Corporation, Tokyo, JP;
Abstract
An automatic analyzer uses probes for detecting liquid levels based on a capacitance detection method. Erroneous detection of liquid levels due to interference caused by the frequency difference of oscillators is reducted. When frequencies fand fof respective detector oscillators, which are originally equal to each other, are different by approximately several Hz from each other due to a manufacturing variation, oscillation waveforms are added to liquid level detection voltages, causing a premature determination that the probes have contacted the liquid surface before actual contact therewith. By setting the difference between the frequencies fand fof the detector oscillators to be in the range of several kHz, an oscillation waveform corresponding to the difference between the frequencies is added to the detection voltages, but the amplitude values of the high-frequency components are attenuated by high-frequency attenuators, thereby ensuring accuracy in the liquid level detection.