A relative-distance pickup, includes a housing, a spring disposed in the housing, a feeler tip disposed in the housing and movable in longitudinal direction of the housing against the spring, an indicating device for registering relative motion of the feeler tip with respect to the housing, the feeler tip being subdivided transversely to the longitudinal direction of the housing forming first and second feeler tip parts, the second part having a stop, the first part being connected to the indica...

The sensor is particularly suitable to determine movement between a ground vehicle or aircraft over a ground surface, and a portion of the reference surface (10) is imaged on a grid plane (12, 30, 40) which, in accordance with the invention, is formed as a photo-sensitive transducer, for example a plurality of photo-sensitive diodes formed on a single chip and suitably connected in a grid or matrix pattern, made, for example, by a planar process by monolithic integration. Correlation-optical mea...

An objective lens of large relative aperture comprising, from front to rear, a first lens component of positive power, a second lens component of positive power and a third lens component of negative power, the first and third lens components being moved forward as a unit, while the second lens component is simultaneously moved forward by a smaller amount than that of the movement of them to effect focusing from infinity to shorter object distances. The focal lengths of the first, second and thi...

A relative humidity sensitive material comprises a mixture of at least one hygroscopic salt and an at least partially electrically conductive metal based powder. Each salt in the relative humidity sensitive material has a cationic constituent selected from the group consisting of the alkali and alkaline earth metals and an anionic constituent selected from the group consisting of a chlorate, perchlorate, and chloro aluminate. The metal based powder preferably comprises a metal or metal oxide pow...

A relative horsepower indicator is used with an electrical model of a reciprocating gas compressor. A voltage representing the cylinder motion is modified and multiplied with a voltage representing the cylinder pressure. The result is calibrated to indicate one hundred percent cylinder horsepower when the model is operated under ideal conditions. The indicator is then used to indicate deviations from this ideal operating mode when the compressor model is used in a complete pumping system model.

A monitor for detecting the relative velocity between a moving body or surface and a fixed body or surface includes a sensor having an actuator member, such as a wheel having magnetic pole pieces embedded therein and mounted for rotation proportional to the relative velocity between the two bodies or surfaces, and a pick-up member such as a coil or inductor, mounted adjacent the actuator for producing an electrical signal in response thereto. An electric circuit is connected to the pick-up membe...

The monitoring system disclosed herein comprises apparatus for transmitting a polarized and modulated light beam from a source at the one monitoring point and splitting the light beam into a plurality of beam portions having different spectral ranges or colors. Each color is directed through one or more transducers, positioned at the other monitoring point, which modify the polarization of the light beam portion. Each transducer is of a type such that the amount of birefringence depends upon the...

An apparatus and method for measuring the velocity of a relative movement between first and second bodies or between a first body and a fluid. The first body may be stationary and the second body a moving body, such as hot strip steel. Alternatively, the first body may be an aircraft or ship whose velocity is to be measured or it may be a pipe or duct along which a fluid is flowing. At least two detectors are mounted on the first body and serve to detect noise signals representing disturbances i...

An apparatus is provided for the measurement of relative displacement between two surfaces, and includes an adjustable reference structure associated with the first surface, a planar guide structure having reference planes associated with the second surface, and a measurement block. A method for obtaining the measurement of the relative displacement between two surfaces is also disclosed.

The equilibrium relative humidity over a substance may be determined by the following method. The sample of the substance is placed in a lower compartment of a diffusion chamber and a dried gas is then passed through an upper compartment of the chamber which is partitioned from the lower by a disc of water vapor permeable non-hygroscopic material. When the rate of diffusion of water vapor through the disc from the lower to the upper compartment becomes constant the equilibrium relative humidity ...