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:
Aug. 01, 1989
Filed:
Apr. 01, 1987
Hans-Dieter Mayer, Baltmannsweiler, DE;
Klaus Hirrlinger, Esslingen, DE;
Abstract
Monitoring a room is accomplished by measurement of air pressure where air passage resistance between a secured room and an outside atmosphere is measured and an alarm actuated, if the air passage resistance drops below a predetermined value. Evaluation of typical air pressure fluctuations in a frequency range between 0.01 Hz and 10 Hz is advantageous. The air pressure resistance may be determined by difference measurements of air pressure fluctuations in the outside atmosphere and the secured room, or as a singular process wherein a connecting tube is provided between the room to be secured and the outside atmosphere, where air movements varying as a function of air pressure fluctuations are measured. Devices for the carrying out of the process are described. The devices and the process provide a simple and cost effective alarm system that operates reliably and is secure against outwitting and sabotage.