Abstract: Apparatus for measuring metallurgical properties of a ferromagnetic test piece that includes a variable frequency oscillator for providing a periodic signal, and a test coil arrangement for applying the periodic signal to a test piece to generate eddy currents therein. A test signal is developed in response to eddy currents induced in the test piece and fed to a microprocessor-based digital controller. The digital controller is coupled to the oscillator for generating the oscillator periodic signal at successive first and second test frequencies. At least two harmonic components of the test signal are separated from each other by the digital controller at each test frequency.

Abstract: An electro-optical sensor for measuring distance to a test surface, such as a road surface beneath a vehicle frame on which the sensor is mounted. The sensor includes a modulated light source for directing a light beam onto the test surface, and a photosensitive detector for receiving light diffusely deflected from the test surface and providing a pair of output signals indicative of orthogonal position coordinates of reflected light incident on the detector. The detector outputs are fed to amplifiers for obtaining sum and difference signals which are demodulated synchronously with energization frequency of the light source. Distance to the test surface is determined as a function of a ratio of the detector output differential to the detector output sum. In the preferred application of the invention for road profile measurement, a signal indicative of road profile is stored at increments of vehicle motion along the road surface.

Abstract: Apparatus for measuring friction characteristics of a vehicle-travelled surface comprising a wheeled vehicle having a test wheel assembly pivotally suspended therefrom by a parallelogram suspension arrangement. The test wheel assembly includes a test wheel carried by a drive shaft which is driven at predetermined slip by a differential coupled to the vehicle wheels. A gear chain extends from the differential to the drive shaft through a housing which forms one arm of the suspension. The second arm is formed by a rod which extends from the differential to one section of a two-axis strain gage wheel force transducer at the test wheel assembly. The differential is suspended by parallel struts from the vehicle frame. A positive displacement pump is coupled to the differential for placing a film of water beneath the test wheel having a thickness which is independent of vehicle speed. The pump and test wheel are clutch driven.

Abstract: Method and apparatus for measuring conductivity of test materials at a measurement temperature and displaying material conductivity at standard temperature by compensating the measured conductivity for conductivity changes due to the measurement-standard temperature differential. This is accomplished by developing a first periodic signal having a period which varies as a direct linear function of material conductivity C.sub.T at the measurement temperature, and a second periodic signal having a period which varies as a function of the product of measured conductivity C.sub.T, the measurement/standard temperature differential .DELTA.T and a conductivity constant .beta. characteristic of non-ferrous metals having a given base metal. Standard conductivity C.sub.S is then determined in accordance with the equation C.sub.S =C.sub.T (1 +.beta.C.sub.T .DELTA.T) as a combined function of the periods of the first and second signals, and is displayed in percent IACS at 20.degree. C.

Abstract: A fully automatic penetration hardness tester which includes a penetrator and clamp driven by respective serially-connected pneumatic cylinders for engaging test specimens. Pressure regulators are coupled to the respective cylinders for first applying clamping pressure against the test specimen and then applying a plurality of loads in a predetermined sequence to the clamped specimen through the penetrator, with the total clamping and penetrator pressure against the test specimen remaining constant through the test cycle. A control circuit monitors penetrator position and automatically initiates application of the next load in the test sequence when motion of the penetrator following application of the preceding load has settled such that a predetermined number of sequential position readings fall within a preselected position range. Specimen hardness is determined as a linear function of penetration depth under the various loads.

Abstract: Electro-optical apparatus, system and method for measuring distance to a relatively moving surface, such as distance to a road surface from a vehicle frame of reference passing thereover. The apparatus includes a light transmitter for projecting a rectangular beam vertically downwardly onto the road surface. A rotating scanner includes a circumferential array of facets for sequentially receiving the image diffusely reflected from the road surface and reflecting such image through a rectangular reticle onto a photodetector. Reference beams are sequentially reflected by the road image-reflecting scanner facets onto a reference detector. Distance to the road surface is then determined as a function of the angle of incidence of the road image onto the scanner by comparing the time of incidence of the road image to the times of occurrence of the reference reflections on the reference detector.

Abstract: A semi-automatic penetration hardness tester for measuring hardness of a test specimen in a selected one of a number of hardness number scales. A digital display indicates penetrator displacement during application of a minor load in a first mode of operation and may be monitored by an operator to achieve a penetrator displacement within a preselected range corresponding to application of a minor load of desired magnitude. A control circuit senses manual initiation of a major load application and automatically scales the minor load penetrator reference position to a reference hardness number corresponding to and correlated with the selected hardness number scale. The control circuit also senses an operator error during the test procedure and automatically aborts the test.

Abstract: A method and apparatus for measuring conductivity of nonferrous metals using eddy current test principles in which conductivity is measured as a direct linear function of the period of the inducing signal at a preselected phase angle between the inducing and induced signals and is displayed directly in percentage of the International Annealed Copper Standard.