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A liquid level detector of the type in which a magnetostrictive wire extends through the liquid level measurement range and is captured in a tensioned vertical orientation within a stainless steel tube. Liquid level is measured as a function of the time required for a torsional disturbance imparted

A liquid level detector of the type in which a magnetostrictive wire extends through the liquid level measurement range and is captured in a tensioned vertical orientation within a stainless steel tube. Liquid level is measured as a function of the time required for a torsional disturbance imparted the wire near the top to travel along the wire to a magnet which is contained within a liquid level float which slides up and down along the tube. The torsional disturbances imparted to the wire by means of a piezoelectric crystal to which the wire is easily clamped. Accuracy is enhanced by measuring liquid level as a function of the elapsed time between an actuation signal and the first zero crossing of the voltage which is induced as the torsional strain passes through the area of influence of the sliding magnet.

대표청구항 ▼

A position transducer of the type which comprises a housing, a magnetostrictive wire disposed within the housing and mechanically anchored at opposite head and foot ends and defining a position measurement range between said ends, a magnet displaceably mounted on the housing for linear displacement

A position transducer of the type which comprises a housing, a magnetostrictive wire disposed within the housing and mechanically anchored at opposite head and foot ends and defining a position measurement range between said ends, a magnet displaceably mounted on the housing for linear displacement along the wire, and signal process means for producing a signal representative of the position of the magnet along the wire, wherein the improvement comprises: actuator means for imparting a torsional strain to the wire adjacent the head end, the actuator means comprising a piezoelectric crystal, clamping means frictionally holding said wire to said crystal, said clamping means including a first lower pad of elastomeric material between a base portion and said crystal, a second upper pad of elastomeric material and a removable clamp plate, and means for applying an actuation signal to the crystal to translate a surface of said crystal transverse to the linear axis of the wire thereby to twist the wire in the locale of the crystal.