The present invention is directed to a method for determining the presence of an oxidant or reductant in a sample by contacting the sample with a thin film of polyaniline in the reduced state or oxidized state, respectively, and measuring the color change occurring with the oxidation or reduction, respectively, of the polyaniline film.

118,882. Parnacott, A. E. Sept. 12, 1917. Viscosimeters. - Apparatus for detecting leakages of air or for measuring the viscosity of liquids comprises a capillary space between a surface and a transparent plate, a thin film of liquid in the space, and means for admitting air or gas to the space. In the form shown in Fig. 1, for detecting leakage through sparking-plugs, the transparent plate c rests on a surface b of a member a connected to a tube j having a collar for a washer to make a sealed joint with the plug or plug-carrying member. In a viscosity meter, a film f<1>, Fig. 4, of the liquid to be tested is disposed between a transparent plate c' and the bottom of a jacketed cup a', variable air pressures being exerted on the film by varying the immersion of a calibrated tube j<1> in a vessel k. In a modification, the pressures are produced by a hand-pump, and the viscosity is indicated by a pressure gauge.

1418835 Gas detector HONDA GIKEN KOGYO KK 5 June 1973 [13 June 1972 (2)] 26878/73 Headings G1B and G1N A gas or vapour detector finding application in testing for alcohol in a driver's breath, is illustrated with reference to Fig. 1 and comprises a body 4 having at one end an inlet 1 and having its other end formed to serve as a hand grip 2. Positioned within the body are:- a suction fan 5 for drawing in gas or vapour, a gas or vapour sensitive semi-conductor element 6 located downstream of the fan, a compartment for an energy source (e.g. batteries 3) for operating the fan, indicator components 7, 7a, 7b for indicating sensing of gas or vapour, and an operating switch mechanism 8, 8a, 8b. An exhaust opening is provided at 11. To prevent cooling of the semi-conductor by the gas flow, there may be provided an obstructing plate (13).

A detector of linear or rotary displacement comprises at least one sensing element at least partially provided by a conventional thin film module, and having at least one thin film, the sensing element can include a resistor or a capacitor arranged to be partially immersed in a liquid in a container. In Figure 1, resistors 11, 12 on a substrate 14 are partially immersed in a conductive liquid 20 (having a surface 21) in a container 22. When the container is tilted the immersed portions of resistors 11, 12 increase or decrease respectively. The ratio of the resistances of the non-immersed portions, measured by a bridge indicates the degree of tilt. In a capacitive sensor, a conductive thin film can be covered by dielectric and a conductive liquid, such as mercury, placed in the container.

Bei einem Sensor (12) zur Bestimmung des Drucks oder der Kraft wird auf einem Träger (10) ein Dickschichtwiderstand (11) aufgedruckt. Mit Hilfe von Leiterbahnen (26) wird das Meßsignal vom Dickschichtwiderstand (11) zu den Ableitungen (17) geführt. Die Kontaktstelle zwischen den Leiterbahnen (26) und den Ableitleitungen (17) liegt außerhalb des direkten Kraftflusses, so daß eine homogene Lastverteilung über den gesamten Bereich des Dickschichtwiderstands (11) möglich ist. In a sensor (12) for determining pressure or force a thick-film resistor (11) is pressed onto a carrier (10). The measurement signal is led from the thick-film resistor (11) to the terminal leads (17) with the aid of printed conductors (26). The contact site between the printed conductors (26) and the terminal leads (17) is situated outside the direct flow of force, so that a homogeneous load distribution is possible over the entire region of the thick-film resistor (11).

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.

A spin motor rotation detector for a split phase or two phase motor drive for a gyroscope applies the spin motor supply voltage and the phase winding voltage to a semi-conductor, e.g., the supply voltage is applied as a reference voltage to the gate on a semi-conductor such as a FET used as a demodulator while the phased motor winding provides the source or (signal) input voltage to the FET demodulator. The phase modulation of the phase winding voltage resulting from hunting during operation of the motor is reflected in the output from the demodulator, and the output is applied to a logic level DC output to indicate satisfactory or unsatisfactory speed of operation of the split phase motor during changes in physical orientation of the gyroscope.

1,064,646. Semi-conductor pressure transducers. SIEMENS & HALSKE A.G. Aug. 4, 1964 [July 23, 1963], No. 30698/64. Heading H1K. [Also in Divisions G1 and H4] A semi-conductor electromechanical transducer consists of a junction transistor having a pressure-transmitting needle bearing on the emitter electrode or emitter zone of the transistor whose design is such that the current density in the vicinity of the needle is greater than that in any adjacent surface region. The embodiment shown in Fig. 3 is an oxide-protected NPN silicon planar transistor having a drop-shaped emitter zone 13 formed by diffusion into the base zone 12. The aluminium emitter electrode 14 is similar in shape to the emitter region and its pointed end faces a similarly shaped base electrode 15 to provide a region of maximum current density between the electrodes. The needle is so placed that its axis intersects the line between the tips of the electrodes. Placing the point of the needle in a region of highcurrent density compensates for the loss of sensitivity arising from the use of a blunted needle to avoid damage to the semi-conductor surface. The needle is preferably made of sapphire, ruby, or boron carbide, but may possibly be made of the softer molybdenum. The pressure sensitivity of the transistor varies with its collector current. A suitable direct current bias may be applied to the unstressed transistor so that the transistor may be operated in an area of high-pressure sensitivity. To avoid the use of pressures sufficient to give non- elastic deformation of the semi-conductor this means that the transistor should be operated with the lowest standing collector current consistent with a reasonable current gain. To assist in operating the transistor in the chosen area a mechanical bias may be applied to the needle. To obtain high sensitivity the junctions should be very close to the surface of the transistor provided that they are not so close as to be damaged by the needle. This is essential only in the region of the needle and localized etching may be used so that the needle may be placed near the junction. Many uses of the transducer are suggested-an aircraft variometer is described. The Specification gives the relationship between the collector current of a conventional planar transistor with a horseshoe-shaped base electrode and the position of a needle applied at constant pressure to points across the emitter, base, and collector of the transistor.