Abstract: Ultrasonic imaging system with a linear array having several transducer elements of which a respective group of commonly controlled transducer elements forms one beam aperture and to which one transmitting system and one receiving system is allocated. A delay time is digitally set for each transducer element of the beam aperture and triggered by means of a starting pulse. Always only one group of the transducer elements on the linear array is active and is connected via transmit switches to the transmitting system, and via receiver switches in series with a wiring arrangement to the receiving system. This facilitates the implementation of an ultrasonic imaging system for high ultrasonic frequencies, particularly in the order of at least 30 MHz, in which the use of a switching matrix in the radiation and receiving system is avoided.

Abstract: Ultrasonic imaging system with a linear array having several transducer elements of which a respective group of commonly controlled transducer elements forms one beam aperture and to which one transmitting system and one receiving system is allocated. A delay time is digitally set for each transducer element of the beam aperture and triggered by means of a starting pulse, and the echo signals of the transducer elements of the beam aperture are added and phase delayed by the software. In this manner, an ultrasonic imaging system for high ultrasonic frequencies, particularly at least in the order of 30 MHz is achieved in which transmitting and receiving lens can be created independently of one another in the computer by changing the software, while the hardware remains unchanged.

Abstract: An aerosol detector, for instance a transmission measurement path in a measurement chamber, is provided for the detection of a foreign component in a gas, for instance of incendiary aerosols or smoke in air, and communicates with a reference chamber containing aerosol-free reference gas. The gas in the measurement chamber is periodically exchanged for uncontaminated gas from the reference chamber by a periodical volume alteration of the reference chamber so that, in the presence of aerosols, the aerosol concentration in the measurement chamber and the output signal of the aerosol detector are modulated. The modulation, i.e. the variable portion of the output signal, is an indication of the aerosol concentration or the smoke density. A particularly suitable application is smoke detection in air for the purpose of fire or incendiary reporting or for monitoring air pollution.

Abstract: A gas detecting system for determining the presence and concentrations of a number of selected toxic, combustible, or reducing gases in an atmosphere. The system includes a plurality of semiconductor gas sensors, each of which differs from each of the others in its response to at least one of the selected gases. The system includes a means of processing the responses of each sensor to produce an indication of each of the gas concentrations. The system may also produce indications of the measurement accuracy of each gas concentration, which can be used to determine the presence of gases not selected for detection.

Abstract: The subject invention provides a method and apparatus for the sampling of trace elements in gas, liquids, solids or on surface layers. A collector surface having predetermined absorption characteristics is brought into contact with a material to be sampled. Thereafter, the collector surface is brought into contact with a contact membrane. The contact membrane is heated and swept by a carrier gas from the input head of an analysis apparatus to analyze the sample collected by the collector membrane. Trace elements in the sampling thermally desorbed by the collector surface are put in solution, are subject to diffusion and evaporation by traversing the contact member, and are transported by the carrier gas through a conduit to a gas analyzer for analysis. The use of both a collector surface cooperating with a contact member advantageously regenerates the collector surface so that it may be used in repeated sampling operations.

Abstract: A gas chromatographic detector for detection of compounds which fluoresce as a photo-response to light. The detector utilizes a remotely located light source for fluorescent excitation of a compound in a gas phase, and includes apparatus for the measurement of emitted fluorescence of a gas and for the measurement of transmitted light through a gas. The detector is close-coupled to an output end of a heated chromatographic column and eliminates the requirement of heated transfer tubes between the column and the detector.

Abstract: Device for fatigue-testing a mechanical component by exciting this component (1), to which massive armatures (2, 3) may be attached, using an electromagnetic vibrator (13) fed by a generator, characterized in that the said generator comprises a displacement sensor (14) placed between two parts of a vibrating assembly (1, 2, 3) and generating a sinusoidal signal; a root-mean-square value converter (5) converting this alternating signal into a direct current signal of root-mean-square value; and an analog divider circuit (7) receiving the sinusoidal signal as numerator (8) and the root-mean-square value signal produced by the said converter as denominator (6), with the output signal (9) from this divider (7) being used after amplification (12) to drive the electromagnetic vibrator (13) acting on the vibrating assembly.

Abstract: The grain size is expressed by the diameter of grains demarcated at high-angle grain boundaries, such as ferrite grains in ferritic steels. Ultrasonic waves having a frequency f are propagated through an object to be examined and its attenuation constant .alpha. is determined. Using the ratio f/.alpha. and equationC'.sub.j .ltoreq.f/.alpha..ltoreq.C'.sub.j+lwhere C'.sub.j and C'.sub.j+l are constants and j is a constant between 1 and 4, the order j of the region to which the value of f/.alpha. belongs is determined. Then the grain diameter D is derived from equation ##EQU1## using an integer n.sub.j and constant A.sub.j predetermined for the order j of each region.

Abstract: A method and a device for determining explosivity rate of a gaseous medium with a detecting filament which is heated in said medium by an electric current flowing therethrough. Said detecting filament is ignited through connection to a power supply and power supplied to said filament is regulated so as to maintain constant the resistance thereof. At some successive moments value of a quantity U significant for power supplied to said filament is taken into account. An exponential curve is extrapolated from such values; parameters thereof are identified and introduced in a process function adapted to deduce therefrom an estimation of the initial explosivity rate of said gaseous medium independently of the nature of the explosive gas(es) present therein.

Abstract: The molecular weight of a pressurized flowing gas is determined by means of a vortex tube. The temperatures of the inlet gas to the tube and of its outlet hot and cold gas fractions are sensed by electromotive force-producing temperature-sensing means; the resulting e.m.f.'s are employed to ascertain differential e.m.f.'s and then to form a ratio of differential e.m.f.'s. The ratio is then converted to the molecular weight of the gas, either by means of a pre-established ratio-molecular weight relationship or converter, such as a graph of variance or a mathematical equation, or, preferably, by means of an electric circuit in which the differential e.m.f.'s, the ratio, and the molecular weight are ascertained instantaneously and the molecular weight is simply read off a meter.

Abstract: An annular array ultrasonic transducer is provided which comprises a plurality of concentric rings of piezoelectric material having widths chosen for operation at different depths of focus. The total aperture of the transducer is divided into a plurality of contiguous focal depths. In the near field only the inner element or elements are activated, and rings of increasing radius are added as the depth of focus is increased. The widths of the rings are chosen to keep phase errors across each ring within acceptable limits over the depth of field for which they are energized. The transition depths at which the aperture is changed are chosen to allow rings of manufacturable widths to be employed while maintaining aperture transitions which prevent banding in the ultrasonic image.

Abstract: In ultrasonic echo testing to detect flaws in manufactured articles, raw materials and such it is desirable to maintain a predetermined spacing and relative orientation of the ultrasonic transducer and the surface of the tested article. Thus, automatic scanning of the article by repetitively translating the transducer across its surface is difficult or impossible if the article surface is anything other than flat. Herein, a plurality of satellite transducers are mounted with and around a primary transducer on a motor-adjustable articulated transducer head in ultrasonic test equipment so as to receive part of the main beam echo and thereby produce respective distance signals, which signals are used by control apparatus to control the transducer head adjustment motor and thereby regulate the primary transducer position relative to the tested article.

Abstract: The invention is an apparatus useful in ultrasonic imaging to provide a highly focussed wave with a large depth of field. The apparatus comprises two or more coaxial, curved transducers, each producing adjacent, coaxial fields.

Abstract: A method for analyzing various components in a natural gas pipeline with the aid of a computer controlled gas chromatograph comprising the steps of: (a) providing the computer control unit with a data base for operating the gas chromatograph including at least: (1) periodically causing a sample of the natural gas to be supplied to the gas chromatograph; (2) operating the gas chromatograph to analyze the various components in the natural gas stream; (3) computing the amount of the various components in the natural gas stream; and (4) reporting the amount of components in the natural gas stream.

Abstract: An acoustic emission monitoring system used for monitoring fatigue crack growth in metal or other materials such as occur, for example, in highway bridges during normal traffic loading. The transducers are placed on the plates to be tested to allow detection of acoustic emission from a particular site. By applying specific recognition methods to the acoustic emission AE, detection of flaws can be detected from a random noise background. The pattern recognition technique first subjects the received AE energy to an energy window test and if the energy is within the window, it is subjected to a rate test and if the energy exceeds predetermined rates, it is passed to a location test so as to locate the position of flaws.

Abstract: An apparatus for analyzing a hydrocarbon sample comprising paraffins, naphthenes and aromatics. The subject apparatus comprises means for providing a sample, a polar column, a 13X molecular sieve coated open tubular column, a nonpolar stationary phase column, a valve means, detection means and means for supplying gas.

Abstract: The present invention relates to an apparatus which determines the distribution of the attenuation slope coefficient on a real time basis using the center frequency shift. The phase difference between a received signal and a reference signal is determined using EXCLUSIVE OR gates or an inverse trigonometric relation stored in a ROM. The phase difference is input to a differentiator which outputs the center frequency shift of the received signal on a real time basis. The center frequency shift is input to another differentiator which outputs the attenuation slope coefficient. Thus, the attenuation slope coefficient is determined using simple hardware and without calculating the power spectrum and the first moment.

Abstract: In a method for measuring variations in the output of an internal combustion engine, at least one of signals respectively representing an engine speed, torque, and internal cylinder pressure of the internal combustion engine during the firing strokes of the engine is obtained. A periodical and pulsating change in the obtained signal is detected. A differential value at a portion of the change of the signal having a maximum gradient is then detected. Another method provides measuring variations in the output of the internal combustion engine by calculating the difference between the maximum and minimum values of the change of the obtained signal. Still another method provides measuring variations in the output of the internal combustion engine by correcting the obtained value in accordance with the engine speed. Still another method provides measuring variations in the output of the internal combustion engine by calculating the difference between consecutive changes.

Abstract: The invention provides apparatus and method for measuring the concentration of large particles in a gas which may also contain small particles. The apparatus comprises a triboelectric charging means which effects triboelectric charging of the large particles in the gas, and charge measuring means for measuring charges on the particles in the gas after it has passed the triboelectric charging means. The triboelectric charging means can be a curved section of an air intake duct or the compressor of a turbocharger. The apparatus enables the operation of an engine or other air consuming device to be interrupted when the concentration of large particles in the incoming air is sufficient to damage the engine, but avoids unnecessary shutdowns due to the presence of small particles, e.g. smoke particles, which are too small to damage the engine or other device.

Abstract: The invention provides an apparatus and method for measuring the concentration of particles in a gas using an electrode disposed within but electrically insulated from an electrically-conductive conduit member, a current measuring device and means for maintaining the conduit member and the electrode at substantially the same potential. Flow of gas containing charged particles along the conduit induces a current passing from the electrode through the current measuring device. If the concentration of particles in the gas becomes excessive, the current measuring device activates a warning device or takes other action to prevent damage to any gas-consuming device attached to the apparatus. The apparatus might include an optional ionizer upstream of the electrode to charge the particles in the gas.