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:
Sep. 01, 1992
Filed:
Apr. 10, 1991
Paul D Engdahl, Santa Ana, CA (US);
Roland S McGee, Tujunga, CA (US);
Roger P Engdahl, Costa Mesa, CA (US);
Other;
Abstract
A seismometer system which provides readouts of the time integral (Cumulative Absolute Velocity or CAV) of the acceleration time history of an earthquake. CAV is found to be a measure of the structural damage potential of an earthquake. Three triaxial low frequency acceleration sensors are connected into a digital computer system. Each sensor has a capacitive pickoff, whose capacitances determines the length of an electrical pulse; the pulse gates high-frequency clock cycles into a counter. The counts are summed to give the time integral. A microprocessor provides for periodic re-zeroing and other calibration functions, and for the actuation of alarms, relays and electrical pulses for utility shutoff and the like at predetermined levels of CAV. The acceleration time history of the earthquake is stored in the memory for later retrieval if desired. The whole system is contained in a small inexpensive package.