Abstract: Apparatus for determining an overall dimension of an electrically conductive object includes a support surface for receiving the object, an electrically conductive plate movable toward and away from the support surface along a path normal to such surface, the plate having a facing surface which faces the support surface and a voltage source for applying first and second electrical potentials to the object and the plate, respectively, to establish a voltage therebetween. A transducer is provided for developing a distance signal representing the distance between the facing surface and the support surface. A motor moves the plate toward the object while the object is received by the support surface and circuitry is provided for detecting when the voltage between the object and the plate disappears due to contact of the plate with the object whereby the distance signal at such time is representative of the overall dimension.

Abstract: A lubricating film thickness measuring system and method includes a rolling element bearing having a relatively rotatable electrically insulated inner and outer races forming a raceway therebetween. Rolling elements are movably mounted in the raceway. Apparatus is provided for measuring capacitance across the bearing. The measuring apparatus includes an oscillator circuit and a phase detection circuit and is responsive to a phase angle shift between a first signal going from an oscillator circuit to the bearing and from the bearing to the phase detection circuit, and a second signal received by the phase detection circuit directly from the oscillator circuit. The method involves applying a predetermined electrical signal across the rolling elements and measuring the capacitance across the rolling elements thereby providing a measure of the lubricating film thickness.

Abstract: A glass container inspection machine including a bottle handling mechanism which presents glass containers to a capacitive sensor which provides a voltage signal representative of the thickness of the glass container, a computer which receives the voltage signals, a keyboard for inputting data into the computer, and a display. The thickness of a glass container is measured at four points, and as each point is presented to the sensor, the measured thickness in input into the computer, which stores the sensed voltages, correlates them to the input thicknesses, and calculates a curve used to determine glass thickness from sensed voltage. Alternatively, the minimum and maximum thicknesses of a glass container are measured, input into the computer, the container is passed through the machine, and the computer correlates the lowest and highest voltages sensed with the minimum and maximum thicknesses respectively, and uses this data to generate the calibration curve.

Abstract: A protection device for a waterbed protects the water bladder and water heater from damage due to overheating when a dangerous condition, such as an insufficient level of water within the bladder or an element of the waterbed surroundings interposed between the bladder and the water heater, arises. The protection device employs a detector in the form of two capacitance plates placed adjacent to the water bladder and connected to a circuit which is operative to prevent power from being supplied to the water heater upon detection of a dangerous condition. The capacitance of the detector plates varies with the level of the water within the bladder and with the presence of a surrounding element between the bladder and heater.

Abstract: A device for detecting objects behind a wall or like surface has a multiplicity of capacitor plates at spaced intervals and a circuit for sensing alterations in the dielectric constant of a region of the surface being inspected and adjacent to each of the capacitor plates. A multiplicity of quantitative display elements are arranged at intervals in a visual display, and each display element provides a quantitative value representative of the strength of the signal generated by the associated capacitor plate. Thus, the images in the display elements will increase and decrease to reflect the quantitative signals and effectively image the object being detected.

Abstract: Apparatus and method for determining capacitive and resistive values of an electrical component, such as a fuel level determining probe, includes a waveform generator for subjecting the probe to a time-varying waveform that includes a linearly varying ramp portion and a fixed, constant portion. A selectively controlled sample and hold circuit senses the voltage potential of the probe in response to a zero-crossing detector during the linearly varying ramp portion of the waveform to provide information indicative of the capacitive value and again senses the voltage potential at selected time thereafter during the fixed portion of the waveform to provide resistive value information. The output of the sample and hold is provided to an analog-to-digital converter which provided digital information to a stored-program controlled processor which provides the desired output information.

Abstract: A device for inspecting a glass container to evaluate its wall thickness. The minimum thickness, the maximum thickness and the minimum to maximum thickness ratio are calculated and an inspected bottle is rejected based on one or more of these three parameters.

Abstract: A method for measuring the width of structures in a semiconductor wafer comprises the step of constructing test structures on the wafer shaped to function as moats for confining electrically conductive liquid. The moats have an elongated shape. By measuring the electrical resistance exhibited by the liquid within the moat, the dimensions of the moat and, thus, the other structures on the wafer can be measured.

Abstract: A capacitance sensor for measuring changes in thickness of a dielectric film, such as plastic film, passed through the sensor, having an upper and lower housing projecting from a back plate, the lower housing having an upper electrode surface and the upper housing having an insulator aligned with the electrode surface; the insulator having an electrode conneced to an electrical conductor; the materials for constructing the two housings, the electrode and the insulator all having a coefficient of linear temperature expansion of less than 1.times.10.sup.-6 per degree Centigrade.

Abstract: A probe developing an admittance with a material whose condition is to be continuously measured is capacitively coupled with a variable frequency oscillator, preferably one having a digital output stage, for generating a variable frequency signal having a period varying with the admittance developed at the probe. Both the oscillator input and output are capacitively coupled to the probe. In a preferred embodiment, a set point circuit including a plurality of resistors coupled in parallel with the oscillator output and a plurality of switches coupled in parallel with the probe conductor and each with a different one of the resistor, provides easy circuit adjustment for use of the system with a variety of materials. A preferred digital circuit employing a pair of flip flops, fixed timer and one shot generate a fixed period variable duration duty cycle digital voltage level signal for transmission, if desired, or for conversion into a variable current signal.

Abstract: A capacitance sensor for measuring thickness variations in film materials, having a sensor mounted in a housing plate slot, with an air gap between the sensor and the housing plate, the sensor being affixed to an insulator support plate, the insulator support plate being affixed to the housing plate, with a bottom plate affixed against the lower side of the housing plate, having enlarged openings for permitting the passage of a conductor to the sensor; all of the conductor and insulator materials having a coefficient of linear temperature expansion of less than 1.times.10.sup.-6 per degree centrigrade, the insulator materials having virtually no dialectic variation with temperature.