A device for generating and utilizing voltage pulses for determining the revolutions per minute of a rotating shaft or the number of complete cycles per minute performed by a reciprocating or oscillating shaft, having a solid state radiation source, a semi-conductor element sensitive to the radiation and an opaque member having an aperture therein to permit radiation to reach the element for generating a voltage pulse, the opaque element being driven in synchromism with the rotating, reciprocating or oscillating shaft, whereby by fast switching and electronic summation of the voltage pulses the revolutions or cycles can be counted.

1,189,225. Measuring movement. LABORATOIRE CENTRAL DES INDUSTRIES ELECTRIQUES. July 4, 1967 [July 4, 1966], No.30822/67. Heading G1A. Small movements are detected or measured by a device comprising a photo-conductive and Piezo-electric solid, or thin film semi-conductor crystal, a light-source for illuminating at least one face of the crystal, electrical contacts on either side of the one face or faces, and means for varying in accordance with the movement the area of the face or faces illuminated whereby the frequency of oscillation in the output circuit of the crystal is varied. The crystal which may be a cadmium sulphide mono-crystal and parallel to the hexagonal axis is made to oscillate by the application of a stabilized D. C. voltage and changes of frequency arising from changes of area are detected to indicate the movement of a mask between the source and the crystal. White or green light may be used and intensities are specified. The green light or light of a shorter wavelength may be produced by an electro-luminescent diode. A load resistor is included in series with the crystal, and the end of the crystal connected to the negative terminal may be shaped to concentrate the electrical field and thus facilitate the commencement of oscillation. Practical embodiments in which the light source and the crystal are mounted in an evacuated and temperature controlled chamber are described. The application of the invention to seismographic measurements is referred to. The crystal may be mounted in a beryllium oxide substrate and the contacts may be formed of successive films of indium and of indium/gallium eutectic.

1,199,075. Fluid-flow meters, electrical. NORTH AMERICAN ROCKWELL CORP. July 31, 1967 [July 29, 1966], No.35150/67. Heading G1N. A flowmeter for insertion in a fluid-flow line comprises semi-conductor strips 19, 29 (Fig.1) having Piezo-resistive semi-conductor strain gauges 20, 30 formed thereon by bonding, planar diffusion, or epitaxial growth. The strips may be N-type while the strain gauges are P-type or vice-versa. Each gauge is formed on a face of a respective strip so that deflection of the strips by a flowing fluid produces tensile stress in one gauge and compressive stress on the other. Where the strips cross one another a bead of epoxy resin is provided therebetween as insulation and to prevent relative movement of the strips. The gauges may be connected in a Wheatstone bridge Fig.3 (not shown). The output voltage of which is proportional to the product of the fluid density, the fluid velocity squared, and a calibration constant; and is connected to a meter which indicates flow-rate. The semi-conductor material of the strips or gauges may be silicon, germanium or carbon or other tetravalent element doped with arsenic, antimony, bismuth or phosporous to give N-type or with impurity such as aluminium indium, gallium, or boron to give P-type. Alternatively the semi-conductor strips may not be doped with impurity.

PURPOSE:To detect the steal of corrosive or combustible gases into a panel thereby to prevent a device in the panel from being deteriorated and explosion from taking place by using the principle, in which an electromotive force is generated by the diference in the pH of a solution between the both sides of a glass thin film. CONSTITUTION:A sealed glass thin film container 22 having an internal electrode is charged with such a chemical as is reacted with corrosive gases such as H2S to have its pH varied and as has no combustible and corrosive properties, e.g., a solution of NaOH. An open container 23 having an internal electrode is also charged with the same chemical as that in the container 22. If H2S steals into panel 21 of sealed construction, the chemical in the container 23 reacts with the H2S so that its component is changed as well as the pH value. On the contrary, the pH value of the chemical in the container 22 is invaried. As a result, a potential difference is established between the two chemicals so that a voltmeter 24 connected with the containers 22 and 23 through a wire 25 indicates a preset voltage level.

In a sensor (12) for determining pressure or force a thick-film resistor (11) is pressed onto a carrier (10). When the thick-film resistor (11) is still in the soft state, a force-introducing part (13) is placed onto the thick-film resistor, and the component thus produced is hardened. As a result, a sensor (12) having a virtually uniform load distribution over the entire thick-film resistor is produced, so that its pick-up curve is already linear in the initial range without prestressing.

PURPOSE:To prepare efficiently pure crystal or film by providing mercury in the flat plate-like state in the inside of a housing regulated to the specified atmosphere, dropping liquid substance by which crystal or film is formed on the surface of mercury and thereby forming the thin crystal or film on the surface of mercury. CONSTITUTION:An aq. soln. of molecule making crystal is dropped on the surface of mercury 8 via a nozzle 10 from a feed source 9 of liquid substance. The aq. soln. dropped on mercury 8 is quickly developed on the surface of mercury and extremely thin film or crystal is made. As this time the water droplets of tip part of the nozzle 10 are touched to the surface of mercury by approaching the nozzle 10 to the surface of mercury 8. When DC voltage of about several volts is impressed between the nozzle and mercury 8 from a power source 11, the surface tension of the aq. soln. is decreased and the surface tension difference between mercury and the aq. soln. is made large and thereby the aq. soln. is instantaneously developed on the surface of mercury and extremely uniform from or crystal can be formed.

1346612 Detecting formation of thin films ANALYTICAL INSTRUMENTS Ltd 30 March 1972 [3 April 1971] 8624/71 Heading G1N The presence of a film or layer on a radioactive source is detected by the resulting drop in ionisation current in an atmosphere surrounding the source. A dew point meter is shown, and includes a radioactive source 2, e.g. tritium or nickel 63, and a collector electrode 1, the radioactive source being cooled until a drop in ionisation current collected at electrode 1 is indicated on an indicator 6. The temperature is then noted on a device 8. In Fig.2 (not shown), the output of the amplifier 5 is used to energise a heater to thereby control the rate of cooling of the source 2.

Disclosed is a sensor comprising an insulating substrate, a plurality of electrodes coated on the insulating substrate and formed of a thin film conductor of a metallo-organic compound obtained by a pyrolysis, and a layer formed across the electrodes. The layer formed across the electodes has an electrical property changeable in accordance with an atmosphere. The sensor reduces the affection due to the existence of the step portion, restrains the structural deficiency at the step portion and improves the stability of the change with age. By the metallo-organic compound, the thin film layer can be formed by a pyrolysis at relatively low temperatures, and the electrodes can be formed in various structures and by various producing processes.