Rate of ascent monitor using piezoelectric transducer
OwnerMalcolm Saubolle, Italo De Blasi +1inventors
InventorsMalcolm Saubolle, Italo De Blasi, Stanley Livshitz
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Abstract
A rate of ascent monitor for drivers uses a sound transducer with velocity characteristics, preferably a diaphragm type piezoelectric transducer, to sense rate of pressure change, and a threshold detector connected to the transducer to drive an indicator providing a warning of an excessive rate of ascent. A second threshold detector can be used to discriminate between descending and ascending motion. The device can be a compact wrist mounted unit.
Claims4
A submersible rate of ascent monitor for divers, comprising a body defining a chamber, a diaphragm of a piezoelectric sound transducer closing an opening in said body so as hermetically to seal the chamber from the surrounding water, a piezoelectric ceramic wafer of the sound transducer being bonded to the inside surface of the diaphragm, a low pass filter electrically connected to the transducer output to exclude therefrom signals due to sounds, water movements and impacts, a threshold detector circuit within the chamber and receiving an output of the low pass filter, said threshold detector having a first threshold corresponding to a rate of decrease of ambient pressure indicative of an excessive rate of ascent, and indicator means driven by the threshold detector circuit to indicate an excessive rate of descent.
Dependencies are inferred from the claim text.