A sensor unit is formed by a single integral body obtained by coupling a resiliently deforming portion with a base portion without interposing a soft material therebetween, and a force applied to a probe secured to a front end of the resiliently deforming portion is measured as a change in capacitance of a capacitor constituted by electrodes secured to opposing surfaces of the resiliently deforming portion and base portion. These electrodes are connected to a resonance circuit of a high frequenc...

A current sensor which has a rigid metallic link member having two end portions of conductive material and an intermediate portion of resistive material interconnecting the end portions. An integrated circuit analog to digital converter is mounted on the link member. The converter has analog input terminals for connection to respective ones of the two end portions of the link member and digital output terminals for connection to a processing apparatus.

An inductive sensory system generally includes a sense inductor, a reference sense inductor, an oscillator, a feedback control loop, and a comparator. The oscillator is connectable to both the sense inductor and the reference sense inductor. Upon the oscillator being connected to the reference sense inductor, the feedback control loop establishes a fixed reference level. Upon the sense inductor being connected to the oscillator, the comparator compares the state of the sense inductor against a t...

A method of generating an adiabatic FM pulse, comprising: selecting a starting trajectory for the pulse; and determining a velocity profile along the trajectory by constraining at least a portion of the velocity profile to fulfill an adiabatic condition other than a frequency frame adiabatic condition. Preferably, the other adiabatic condition is one defined in a double-rotating reference frame.

A method for determining the resistivity of earth formations penetrated by a wellbore. Electrical current is imparted to the wellbore and the earth formations from a first electrode located on a mandrel disposed in the wellbore. The electrical current is returned at a second electrode on the mandrel at a spaced apart location from the first electrode. Voltage differences are measured between a first pair and a second pair of electrodes located on the mandrel between the first and the second elec...

A subsurface formation may be evaluated through use of data obtained from Stoneley wave propagation in the fluid column within the borehole. Either wave amplitude or phase velocity may be utilized to determine composite lithology parameters. These composite lithology parameters reflect fluid and/or formation characteristics, and functionally relate such characteristics in a manner as to facilitate the determination of formation permeability in a well logging environment.

In a medium-voltage network, a method and a device for location of a fault on one of the lines having loaded branches. Common voltage and sum current are measured centrally prior to and after the occurrence of a fault. Positive sequence impedance of the line and a fictitious value of the positive-sequence impedance of the line, as viewed from each branch, is determined. A change of the fictitious value of two consecutive branches from a positive to a negative value is interpreted as if the fault...

A circuit board has an arcuate array of conductor segments each subject to a digital waveform differing in phase for the various segments, and a concentric pickup conductor. A rotary encoder disk has a conductive pattern which sums and couples the waveforms from selected segments, depending on rotary position, to the pickup conductor. A synchronous phase detector generates a phase signal from the summed waveforms and the zero crossing of the phase signal is detected. A counter develops count sig...

A knock detection device for an internal combustion engine prevents erroneous knock detection decisions from being made due to an LC resonant current in an ion current path. An LC resonance frequency, which is determined based on an inductance of ignition coil secondary and a stray capacitance formed in the ion current path, is set so as to be displaced from a knock frequency so that the knock frequency component alone can be detected accurately from the ion current output. Preferably, the induc...

A system and method for monitoring the dynamics of particle motion in a liquid-solid media including the rate of settling of particles, the identification of unsettled particle clouds, and the identification and control of the bed level of settled particles in a slurry within a settler is provided. The system includes an ultrasound transducer and a receiver for detecting echoes from particles in the slurry. The echoes are processed to determine the bed level of the settled particles, the positio...