Vickers, Inc.

Nielsen-kellerman Co.

Aeroquip Corporation

Nielsen-kellerman

Paul H Nielsen

Richard Kellerman

Joseph Habib

Harry J Kuhlen

A method and apparatus for measuring relative humidity of a mixture that provides a quick response time for thermal lag while affording protection to fragile sensors. In one aspect, the invention is a method for calculating the relative humidity of a mixture comprising measuring a chamber relative humidity (RHC) within a chamber enclosing an humidity sensor; measuring a first temperature (TC) within the chamber; measuring a second temperature (TA) separate from said chamber, said second temperature being the temperature of the mixture; and calculating the mixture relative humidity (RHA) based on the chamber relative humidity, a first value representing the first temperature and a second value representing the second temperature.

Method and apparatus for measuring relative humidity of a mixture

A method and apparatus for measuring relative humidity of a mixture that provides a quick response time for thermal lag while affording protection to fragile sensors. In one aspect, the invention is an apparatus comprising: a chamber having a membrane covering an opening in the chamber, the membrane being permeable to water vapor while impermeable to liquid water; a humidity sensor for measuring relative humidity of the mixture within the chamber; a first temperature sensor for measuring a temperature relating to the mixture within the chamber; a second temperature sensor for measuring temperature of the mixture at a point exterior to the chamber; and a processor for receiving signals representing the measurements taken by the humidity sensor, the first temperature sensor, and the second temperature sensor and programmed to calculate relative humidity of the mixture at the point exterior to the chamber as a function thereof. The internal surfaces that form the chamber volume are preferably constructed of nonabsorbent material.

An improved speed transducer is disclosed. The present invention provides an alternating current coil speed transducer which utilizes the Faraday Effect to generate a voltage. The present invention discloses an improved amplifying circuit that amplifies the low voltages generated by small boats such as rowing shells to permit them to register accurate speed data at low speeds, e.g. between about 0.5 and 10 m/sec although higher speeds can be measured. The present invention also provides an improved technique for connecting a speed transducer to a boat that permits the speed transducer to be mounted and dismounted and the electrical connection broken without requiring extensive reworking of the speed transducer. In this regard, the present invention generally provides an improved technique for mounting and dismounting protruding apparatus that have electrical or other connections that extend into an object. A boom for mounting the speed transducer of the present invention or other types of transducers to a watercraft at a position outside the hydrodynamic boundary layer are also disclosed.

Faraday effect small boat speed transducer and waterproof connection for

A magnetic sensor for the collection and measurement of ferrous particles through the use of an electronic tuned circuit is disclosed. The sensor contains an electrical inductance coil along with an integral magnet to attract ferrous particles suspended in the fluid. The ferrous particles collecting on the magnetic surface of the sensor causes a change in the inductance of the integral coil which is measured by an electronic circuit. The electronic circuit operating in conjunction with the sensor utilizes a series resonant circuit. A measurement of the voltage across the series resonant circuit is responsive to changes in temperature of the inductance coil. A microprocessor is used to determine the change in period of the resonant oscillation with change in inductance of the coil. The microprocessor uses the data on temperature variation to correct the observed change in oscillator period for the effects of temperature. The sensor may be located in environmental conditions which include a large variation in ambient temperature. The microprocessor may be interrogated to obtain information on the total debris accumulated, the presence of any rapid or large debris accumulation and the variation of the temperature in the probe.

Temperature compensated electrical sensor system for measuring ferrous

A linear capacitance displacement transducer for measuring absolute displacement is formed from a coaxial variable capacitor and a precision capacitance measuring electronic circuit. The plates of the coaxial capacitor are attached to the members of an assembly whose displacement relative to one another is to be determined. Linear displacement of the members causes a linear displacement between the capacitor plates which is reflected in a linear capacitance change. A capacitor controlled oscillator utilizes the coaxial variable capacitor at its input. The capacitor controlled oscillator whose period of oscillation is been determined by the capacitance and locked in phase with changes of capacitance is utilized as a precision measure of capacitance. The period of the square wave output of the oscillator is a linear function of the capacitance of the variable capacitor at any time. The transducer may be adapted to determine the absolute position of a piston rod in a hydraulic cylinder.

Linear capacitance displacement transducer

An optical liquid level sensor utilizing both a prismatic member for the light refraction when immersed in and surrounded by a liquid and its effects for the indication of the presence and absence, selectively, of the liquid level. This level indication is provided in the subject case through a target plate bearing letter codes and legends, respectively, which are recognized and standardized in this trade and which become visible at the onset and for the duration of an acceptable liquid level situation; otherwise; a messageless image appears in the sensor. The illuminated target plate allows also for the observation of the color and any color change of the liquid and the taking of remedial actions.

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Wilmington, DE, United States of America

Paul H Nielsen