942,609. Radiographic techniques. UNITED KINGDOM ATOMIC ENERGY AUTHORITY. July 19, 1962 [Aug. 25, 1961], No. 30703/61. Heading H5R. A method for the radiographic examination of materials having low absorption coefficients comprises contacting the parts to be examined with a volatile radiopaque fluid whose linear absorption coefficient is greater than twice that of the material of the specimen, effecting radiography, and removing the fluid by heating. The method may be applied to beryllium, beryllia or graphite which are commonly used in nuclear reactors, and the liquid, which may be applied by dipping, vacuum impregnation or vapour phase contacting, is a halogensubstituted aromatic or aliphatic hydrocarbon, e.g. carbon tetrachloride, bromobenzene, tetrabromethane or perchlorethylene. Removal of the halogen compounds below a level of 10-20 p.p.n. is effected by a simple treatment in a vacuum furnace at 95‹ C. for 30 hours, or at 400‹ C. for 2 hours. To detect microcracks, a thin film of the liquid is trapped over the surface of the specimen by using a transparent impermeable envelope, e.g. Cellophane (Registered Trade Mark).

486,851. Telescopes. REASON, R. E., and KAPELLA, Ltd. Dec. 11, 1936, Nos. 30740/36 and 663/38. [Class 97 (i)] In a sighting telescope, particularly for measuring the angular or lateral displacement of a member by observing the displacement of the image of a mark &c. formed by an objective in the telescope, the observing system is provided with means for reversing the displacement of one portion of the image relatively to that of the other portion and means are also provided in the telescope whereby the two portions are brought into superposition or into alignment with one another. Fig. 1 shows a form in which the mark is within the telescope and consists of a slit D illuminated by a lamp C and condenser C<1>. The rays are directed along the axis of the telescope by a thin film E constituting a semi-transparent mirror. The optical distance from the slit to the telescope objective A is equal to the focal length of the objective so that the rays on emerging from the objective are parallel. These rays are received by a mirror F on the member whose angular position is to be measured and are returned through the objective to form an image in the focal plane. In this plane the rays are divided, for example by a pair of segmental lenses G<1>, G<2>, and the two beams pass to an objective H having its principal focus in the plane of the image, and thence through apertures J<1>, J<2> in a screen J to an objective H<1> forming a second image, the beams being recombined at such image by a biprism K and transmitted to an eyepiece K<1>. Between the objectives H, H<1>, one of the beams passes through a reversing prism L<1> and the other beam passes through a glass block L to equalize the ray paths. To bring the two half images into alignment, a prism M displaceable along the axis of the telescope is provided, this prism being provided with a pointer M<1> which indicates on a scale M<2> the displacement of the mirror F. Instead of an auto-collimating telescope as above described, a focusing telescope as in Fig. 3 may be used in conjunction with a sighting mark on the object whose displacement is to be measured. In Fig. 3, the whole of the ray-dividing and observing system is mounted in a tube S which can be moved axially for focusing by a rack S<1> and pinion S<2>. To prevent lateral errors in the focusing movement the tube S is mounted in the tube B in two bearing rings T having sharp-edged recesses T<1>, Fig. 4, constituting a four point support, against which the tube is pressed by springs U acting through balls U<1>. To enable this instrument to be used alternatively as an auto-collimating telescope, a slit D and lamp C may be provided. Specification 430,761 is referred to.

978,143. Electric meters; electric bridge circuits; liquid level measuring apparatus; indicating apparatus. BENDIX CORPORATION. March 14, 1963 [March 26, 1962], No. 10212/63. Headings G1J, G1N, G1Q and G1U. [Also in Divisions G4 and H3] The output voltage of a capacitive liquid level measuring bridge uses a circuit comprising a number of transistors of opposite conductivity type are arranged in cascade such that as the D.C. input signal rises the output voltage first rises and then falls. Fig. 1 comprises two such cascades in succession so that the final output voltage rises and falls twice. It is explained mathematically that so long as the signal voltage is below the level at which the respective output transistors 59 and 72 saturate the gain of each circuits is 2 but when they saturate the output voltage (e.g. E2) is related to the input voltage (e.g. E 1 ) by the relation E 2 = V - 2E 1 where V is the supply voltage. The circuit is used to measure the voltage from a liquid level indicator Fig. 3. The liquid level measuring capacitance 81 is connected in a capacitive bridge fed with alternating current from source 84 and having its output amplified at 85 rectified at 86 and 90 and then applied across a potential variable capacitor 83 in the form of a semi-conductor diode so as to balance the bridge, isolating chokes being provided to separate the A.C. path from the D.C. path. Rectified output from the amplifier is fed to a first meter 93 calibrated in metres and through a folding circuit similar to Fig. 1 to a meter 95 calibrated in decimetres. As the level of the liquid rises from 0 to 1 metre the pointer of meter 93 moves clockwise from 0 to 1 and the pointer of 95 moves in clockwise direction from 0 to 10. A further rise of 1 to 2 metres increases the reading on 93 from 1 to 2 but, as the output of the folding-circuit is now falling, causes the pointer of meter 95 to rotate in an anticlockwise direction towards its initial position, readings being taken from the inner scale. Further rise from 2 to 3 metres causes the pointer of metre 95 to move clockwise again while the rise from 3 to 4 metres causes pointer of metre 95 to return in an anticlockwise direction.

At least part of a readout pattern including carrier collecting electrodes, capacitors, thin-film transistors, data lines and gate lines is formed by vapor deposition or printing. This is formed separately from a semiconductor thick film. The semiconductor thick film and readout pattern constitute a flat panel X-ray detector (FPD) is mounted in a case to form a unit. A weight reduction is achieved by using the semiconductor thick film in place of a conventional glass substrate. The FPD manufactured in this way is free from great restrictions in time of transport and use.

1,020,974. Magnetic tests. SIEMENSSCHUCKERTWERKE A.G. Oct. 26, 1964 [Oct. 26, 1963], No. 43638/64. Heading G1N. [Also in Division H1] An indication of the gradient of a magnetic field is given by a meter 9 connected across a bridge circuit containing two probe arms 1, 2 joined by a bridge 18, the probe arms and the bridge being formed integrally from a single piece of magneto-resistive semi-conductor material, such as indium antimonide. The bridge 18 is metallized, and mutually parallel strips of good conductivity may be mounted on or embedded in the probe arms 1, 2 at right angles to their axes. Two such devices, possibly formed from a single piece of semi-conductor material, Fig. 4 (not shown), may be combined to measure the second derivative with respect to distance of the magnetic field.

PURPOSE:To judge a peeling point of a thin film from a base material while enabling accurate measurement of a peeling load by determining a testing point with an optical monitor to apply a peeling load to a plane indenter after it is bonded on a thin film sample. CONSTITUTION:An optical image of a base material sample 17 formed with an optical monitor 30 is taken with a TV camera 33 to be stored into an image memory 35 and projected onto a CRT 36 to determine a testing position of a thin film on the surface of the sample 17. Then, the thin film is bonded on a plane indenter 7 by putting an adhesive on the plane indenter 7. A load is generated with a load current feeder 13 so as to lift the indenter 7. In this manner, a tensile load is applied continuously to the thin film to measure a load as peeling load at which a peeling occurs between the thin film and the base material 17. This enables accurate measurement of a peeling load of the thin film sample thereby accomplishing an evaluation of the strength of the thin film accurately.

995, 252. Liquid level control and indication. HALKERGERHUTTE G.m.b.H. Dec. 21, 1961 [Dec. 24, 1960], No. 45887/61. Heading G1H. [Also in Division G4] A liquid level indicating and/or controlling device comprises a transparent gauge tube 1 connected to the container and containing a float 2 of opaque material when the liquid is transparent and of transparent material when the liquid is opaque and two housings 3,4 at opposite sides of the tube respectively containing a semi-conductor photosensitive means 5 and a convex lens 8 which brings light rays 9 to a focus on the means 5. The photosensitive means may be a germanium photo-diode or a silicon photo-cell. In operation the opaque float interrupts the light rays or, in the case of a transparent float, allows them to pass, when it reaches the level of the housings whereby in each case the means 5 transmits an electrical pulse to an amplifying relay. Housings can be located at desired high and low levels and the relay arranged to stop or start a filling pump and to operate acoustic or visual signals. A number of housings may be arranged on the gauge tube so that switching operations for control and/ or indication may occur at selected levels. The housings may be provided with cooling fins.