The invention concerns a method for testing or measuring electrical elements, wherein a beam (6) of particles is applied to a location of an electrical element (2, 3), charges are released under the effect of the application of the beam (6) of particles, the released charges are collected by a collector (9), the amount of collected charges is measured, and an electrical characteristic is derived from the measurement of the amount of charges collected. The invention is applicable, in particular, to measuring the resistance and/or the capacity of printed circuits, as well as to any other type of substrates such flat displays, circuits equipped with components, semi-conductor chips. L'invention concerne un procédé de test ou mesure d'éléments électriques, dans lequel un faisceau (6) de particules est appliqué à un emplacement d'un élément électrique (2, 3) , des charges sont libérées sous l'effet de l'application du faisceau (6) de particules, les charges libérées sont collectées par un collecteur (9) , la quantité de charges collectées est mesurée, et une caractéristique électrique est déduite de la mesure de la quantité de charges collectées. L'invention s'applique, en particulier, à la mesure de la résistance et /ou de la capacité de circuits imprimés, ainsi qu'à tout autre type de substrats tels que des écrans plats, circuits équipés de composants, puces à semi- conducteurs .

768,296. Electric measuring systems. SIEMENS - SCHUCKERTWERKE AKT. - GES. Jan. 13, 1955 [Jan. 13, 1954; Feb. 10, 1954; Feb. 26. 1954; Feb. 26, 1954; March 4, 1954; April 17, 1954; April 17, 1954; Oct. 30, 1954], No. 1144/55. Class 40 (1). [Also in Groups XXXV and XXXVII] Apparatus for measuring the torque of an electric motor for indicating or control purposes comprises a semi-conductor body transversely located in the magnetic field of the motor and fed with the armature current in a perpendicular direction, whereby a Hall effect voltage is produced in the third perpendicular direction whose magnitude is proportional to the torque produced by the motor. As shown for a D.C. series-wound machine 106 (Fig. 7), the semiconductor body 110 is located between a field pole and the armature, so that the flux passes transversely through it, and an E.M.F. proportional to the armature current is obtained from a series resistor 111 to be fed in at terminals 101, 102 located at the axially opposing edges of the body 110, whereby the Hall voltage appearing at terminals 103, 104 on the other opposing edges is proportional to the torque, and may be used to control full load relay 113, operating a warning lamp 115; and over-load relay 114 which can trip the main switch 112. The longitudinal current through the semi-conductor body 110 may alternatively be obtained through a D.C. transformer comprising an A.C. energized coil wound on a core having a further winding carrying the motor armature current, whereby the impedance of and the current in the A.C. winding is proportional to the D.C. load current, and is rectified before being fed to the semi-conductor body 110. To indicate the power output of the machine, the Hall voltage torque signal obtained from a semi-conductor body 210. (Fig. 9), as described above is multiplied by a speed signal obtained from a tacho-generator 215 driven by the motor (not shown), in a wattmeter-type instrument, or in a multiplier comprising a choke 220 whose energizing winding 221 is fed by the tacho-generator 215, and which has a further semi-conductor body 219 located in an air gap in the iron circuit, fed with the torque signal from semi-conductor 210 at terminals 205, 206 to produce a further Hall voltage at terminals 207, 208 indicative of their product and representing the power output. Alternatively the torque and speed signals may feed the field and armature of a motor driving a meter pointer through a clutch which is energized separately for each operation, so that the total work done during each operation may be determined. In an embodiment for maintaining a constant tension in steel strip rolling apparatus (Fig. 12), the strip, initially on a reel 309, is fed between rolls 325, 326 to a reel 328. The rolls 325, 326 are driven at constant speed by motor 310; the reel 328 is driven by a motor 311; the reel 309 is located on a shaft carrying a motor 312 which acts as a generator brake when strip is being fed in the direction shown, the functions of motors 311, 312 being reversed when the direction of winding is reversed. The torque output signal of motor 311 is combined with the speed signal produced by a tacho-generator 322 in a second semi-conductor device 319 to obtain a voltage at terminals 307, 308 representative of the work done by motor 311, which is compared at resistor 324 with a voltage from tacho-generator 323 driven by the motor 310, any difference being applied to the control grid 315 of a mercury arc rectifier 314 feeding the armature of motor 311, whereby the winding speed of reel 328 is adjusted to that consistent with a constant tension in the strip. To avoid inaccuracies due to armature reaction the torque-measuring semi-conductor element may be mounted on the rotating armature, connections being made through a combination of slip-rings and commutators, or the load current may be tapped off directly from an adjacent armature conductor. A plurality of seriesconnected, torque-measuring semi-conductor 'elements may be used, located either axially or circumferentially or both on the surface of the armature. Alternatively, to avoid the effects of variable armature reaction, variable speed and variable temperature, the magnetic condition under the pole of a motor 501 (Fig. 15), may be reproduced in a static magnetic core 503, the main flux being produced by a winding 508 in series with the field winding 502, the semi-conductor body 505 being located in a gap 504 and fed with a proportionate armature current from shunt resistor 506, the complete magnetic conditions being simulated by the addition of a saturable leg 509 and a yoke 510 separated by an adjustable insulating strip 511, and auxiliary winding 512 short-circuited through a resistor 513. To determine the torque output of an A.C. motor the semiconductor element is located 90 degrees electrically from the field winding whose current is being fed to the semi-conductor body, so that its instantaneous magnetic flux is that produced by the instantaneous current through it, which therefore bear the correct phase relationship.

A pore- or particle-size distribution measurement apparatus is provided. When the size of a pore existing in a porous insulator film or the size of a particle in a thin film is measured, a specimen having the insulator film on the surface of a substrate is irradiated, from the surface side thereof, with X-rays at a specified incident angle larger than the total reflection critical angle of the insulator film but less than 1.3 times the total reflection critical angle of the substrate. In the irradiated X-rays, among components exiting from the insulator film without entering the pore and scattering of reflection component of the X-rays reflected on the surface of the substrate after having entered the insulator film, the scattered component whose exit angle is larger than that of a component of the reflection component which exits from the insulator film without entering the pore is detected.

PURPOSE:To speedily measure the state of corrosion by forming a sample to be measured in a thin film and measuring an increase of the electric resistance resulting from the corrosion. CONSTITUTION:A metal to be tested is deposited as a thin film 2 on a non- conductive substrate 1. Terminals 3 are connected to both ends of the thin film 2, thereby forming a sample 4 to be tested. While the sample 4 is left in the air in the similar manner to the air exposure test, an electric resistance measuring device 5 is connected to the sample 4 and the resistance is measured sequentially with time. Accordingly, since the resistance value is increased by the reduction of the thin film 2 as a result of corrosion, the amount or degree of corrosion with time can be calculated in accordance with a predetermined formula thereby to measure the durability of the metallic shcathing.

853,329. Correspondence control devices. ULTRA ELECTRONICS Ltd., [formerly ULTRA ELECTRIC Ltd.]. April 17, 1959 [May 21, 1958], No. 16337/58. Class 40 (1). In a transducer utilizing either the Hall effect or the magnetoresistive effect, a semiconductor lamina is embedded between two high-permeability semicylindrical members 1, and spaced from the circumference and ends thereof, and the cylindrical rotor thus formed is mounted between the poles 2 of a magnetic circuit so as to be rotatable about its own axis. The Hall voltage output, or the semi-conductor resistance, depends upon the magnitude of the component of magnetic flux normal to the lamina, i.e. upon the angular position of the rotor. Preferred semi-conductor material for the lamina is an alloy of elements of Group III and Group V of the Periodic Table, e.g. indium arsenide or indium antimonide. When Hall effect is utilized, the transducer output, which passes through zero and is bidirectional, may be connected in opposition to an external signal source, e.g. a thermocouple, to produce a differential control signal. When the magnetoresistive effect is used, the semi-conductor lamina may be connected in a bridge circuit comprising a similar lamina; this arrangement gives a null output at zero setting with temperature compensation. The cylindrical rotor produces a sinusoidal output; if an output with an extended linear portion is required, the shape of the rotor may be modified, or a suitable mechanical link or cam arrangement may be used.

788,538. Heat conduction manometers. HERAEUS GES., W. C. April 26, 1954 [April 25, 1953; Nov. 27, 1953], No. 12001/54. Class 40 (1). In a heat conduction manometer comprising a casing 7 containing a sealed measuring chamber 8 communicating only with the pressure chamber and a similar reference chamber 9 containing gas at constant pressure, the chambers each contain a small semi-conductor bead supported by thin electrodes. The beads 1a, 1b form the measuring and reference arms respectively of a Wheatstone bridge which is provided with a positive temperature coefficient resistor 20 in parallel with the bridge instrument to compensate for changes in ambient temperature. Through each of electrodes 2a, 2b, which are preferably of Pt or Pt alloy not more than 25 thick and circa 25 to 50 mm. long, heat conduction is less than 4 x 10-7 cols./‹ C. temperature difference between its ends, and thus no greater than the heat loss through the gas the variations of which with pressure make the measurement possible. The casing 7, e.g. of brass or Cu which may be water cooled to maintain its temperature constant, is fixed to a flange 6 having a hole communicating with vacuum chamber 23. To stop bead poisoning and electrode corrosion any vapours present in the chamber are condensed on cooled baffles in the communication hole. The other bridge resistors may be external to or contained within the casing 7. Compensation for variations in sensitivity and of the zero point with such changes in ambient temperature as may occur may be effected by placing positive temperature coefficient resistors, e.g. 18 and 19, in the other bridge arms in series with the normal balancing resistors 14, 15 which may also have positive temperature coefficients and making one, 18, adjustable; by a temperature sensitive resistor 22 in series with the bridge instrument; by a negative temperature coefficient resistor 21 in the supply line of the bridge; or as shown by a combination of all these methods. In an alternative arrangement, the bridge instrument is replaced by an amplifier to permit of indication at a remote point.

A dielectrically isolated, pressure responsive silicon diaphragm includes a single crystal substrate bonded to a single crystal strain gage component with an intermediate insulating layer and glass bonding layer. The boric oxide enriched glass has a lower softening temperature than the insulating layer and semiconductor and a matching expansion coefficient. Illustratory products are integral silicon diaphragms, integrated circuits, and power devices for high temperature applications where junction isolation is useless. In the method of fabrication the composite is bonded at elevated temperature under pressure and the temporary substrate is removed mechanically and by a final preferential etch. Active components with thinner semi-conductor layers of uniform thickness can be produced.