Abstract: The invention relates to a multichannel spectrometer (10), in particular for examining moles (16) having an evaluating and display device (14) and optical means (18, 19, 21, 23, 22) to determine and display reflectance spectra of a skin surface on an ascertainable image plane (x,y) while considering white standards (17).

Abstract: A sensor includes a pair of resiliently loaded jaws for receiving a finger, the sensor including a pair of fiber optic light transmitting guides secured in fixed spaced relation to one of the jaws for sensing blood in the finger tip. A control unit includes a light generator for transmitting light modulated at first and second frequencies to one of the guides via a light guide transfer section. The finger pulse modulates the received transmitted light. The modulated light is sensed by the other guide and returned to a receiver in the control unit via the transfer section for separating and demodulating the different frequency signals. The control unit includes a calculating unit which has two branches for processing and then combining by dividing the processed demodulated signals for determining the oxygen content of the blood from the relative magnitudes of the pulse-dependent modulation factor of the wave reflected from the finger.

Abstract: An X-ray apparatus comprises a polychromatic X-ray source for generating a primary beam of small cross-section, an energy-sensitive detector arrangement for detecting the scattered radiation produced by elastic scattering processes in the primary beam, which detector arrangement comprises a plurality of detector elements which are arranged on rings concentric with the primary beam, and a collimator arrangement which is arranged between the X-ray source and the detector arrangement and which encloses the primary beam. In order to enable accurate determination of the pulse transfer spectrum while using a low dose, the collimator arrangement is constructed so that the scattered radiation from the same section of the primary beam is incident on a plurality of detector elements.

Abstract: An apparatus for driving a plurality of motors at different variable speeds. The apparatus includes a rectifier for supplying direct current power to a dc bus circuit. A plurality of inverters are connected to the dc bus circuit and each inverter drives a respective motor. Each inverter is controlled by an individual controller connected thereto for controlling the frequency of the output of the inverter to thereby control the speed of the associated motor. The inverters are preferably mounted on a common heat sink to reduce electrical and mechanical complexity. The apparatus permits the rectifier and the dc bus circuit to be sized to handle a maximum rating of less than the sum total of maximum loads of each of the motors. The dc bus circuit also serves to distribute energy generated by a slowing motor, for example, to other motors driven from the bus circuit. A chopper resistor may be included and switched across the dc bus circuit to provide braking to the motors.

Abstract: The invention relates to an optical sensor arrangement having a light emitting arrangement (2), which feeds a first emission light beam into a first emission optical waveguide (3) and a second emission light beam into a second emission optical waveguide, having a polarizer (5), which is coupled with the two emission optical waveguides and generates from the first and second emission light beam a respective linearly polarized light beam, and having an optical sensor (1), which alters the state of polarization of a supplied polarized light beam as a function of a physical quantity acting on the sensor and which supplies a sensor light beam formed from a polarized light beam. Behind the optical sensor (1) there is disposed an analyzer (7), which separates each sensor light beam into two linearly polarized reception light beams, one of which is fed to a light receiving arrangement (12) via a first reception optical waveguide (9) and the other via a second reception optical waveguide (11).

Abstract: A method of stress-optical force measurement where a linearly polarized light ray is guided into a stress-optical measurement array consisting of several measurement members on which the force to be measured acts in a distributed manner. The light ray successively traverses the measurement members while being influenced in a force-dependent manner and is applied to a subsequent evaluation unit for evaluation. The invention also relates to a measurement device for performing the method, comprising a measurement array and an evaluation unit between two plates which are arranged in parallel at a distance from one another. The measurement array consists of at least three spaced stress-optical measurement members which keep the plates at a distance from one another, influence the light ray in a force-dependent manner, and guide the light ray into the evaluation unit arranged between two measurement members.

Abstract: The invention relates to a fiber-optical sensor, comprising a light transmitter device (6) which couples transmitted light into at least one first ligthwave conductor (3,4) and also comprising a light receiver device (7) which receives light from the first lightwave conductor and at least one second lightwave conductor (4,3). The lightwave conductors (3,4) comprise adjacently situated portions (1) which can contact one another in a light-transferring manner at given areas and which are accommodated together in an envelope (5) at this area, a force or a pressure being applied to the lightwave conductor via said envelope. The light transmitter device (6) also couples a first transmitted light into the first lightwave conductor (3,4) and a second transmitted light into the second lightwave conductor (4,3).

Abstract: During the transmission of measurement values of a sensor from a transmitter circuit to a receiver circuit, for example via an optical fibre, use has been made of a device which must be activated by the receiver circuit before a measurement value can be transmitted. This is done in order to achieve potential freedom. The novel device for transmitting the sensor measurement values aims to operate faster and independently of the receiver circuit. The sensor (1) is activated by control pulses generated by a pulse generator circuit (3) and applies to the pulse generator circuit, during the occurrence of a control pulse, a measurement pulse which is dependent on the measurement value circuit. The repetition frequency and/or the width of the control pulse then depends on the amplitude value of the measurement pulses.

Abstract: A method of transmitting at least two measured values by means of light pulses which are passed by an optical transmitter through an optical transmission path to an optical receiver and whose relative separation in time is proportional to the measured value. The energy consumption for the optical transmission of the measured values is reduced by transmitting needle pulses cyclically, one after another in the same order of succession, in that per measured value an optical measuring pulse is transmitted, whose separation in time from the optical measuring pulse associated with a preceding measured value is proportional the magnitude of the measured value, and in that for each group of measured values an optical identification pulse is transmitted, whose distance in time from a preceding measuring pulse is smaller than the smallest possible distance in time between two successive optical measuring pulses.

Abstract: The invention relates to a method of taking measurements along an optical transmission path by means of an optical sensor. The optical sensor includes an optical converter whose optical attenuation properties can be influenced according to the value to be measured and through which a first beam portion of a high-frequency amplitude-modulated optical transmission beam is passed. A second beam portion of this transmission beam is conveyed via a delay element. The second beam portion is applied together with the first beam portion outputted by the optical converter, via the transmission path as a receive beam to the receiver arrangement. In this way the modulation change produced by the sensor is processed and evaluated as an information about the measure value. Measuring a value at the transmitter end is possible with any optical transmission path of an undefined length, without recalibration of the receiver arrangement, because the optical transmitter beam is additionally subjected to low-frequency modulation.

Abstract: Apparatus for measurement of the stress birefringence of an optical sensor that is influenced by a quantity to be measured. An optical emitting device sends light of two adjacent wavelengths .lambda..sub.1 and .lambda..sub.2 through an emitting light guide and via a polariser and a retarder plate to the sensor. An analyser conducts mutually parallel polarization components of the light emerging from the sensor on a common path to a receiving and evaluating device which derives from the measured-value-dependent intensities of such polarization components information concerning the magnitude of the quantity to be measured. The thickness of the retarder plate is dimensioned to provide a path length w of the light through the retarder plate such that the two light components .lambda..sub.1 and .lambda..sub.2 that leave the analyzer are influenced in mutually opposite senses by the measured quantity via the sensor, so that they do not need to be separated by optical filters and combined again by a coupler.

Abstract: An optical sensor (1) is connected to an electro-optical transducer unit (35) and a measuring circuit (36) via an optical delay line (14) and an optical path (15). Error-free measurement values which are independent of the attenuation characteristics of the optical delay line (14) are obtained if the optical sensor (1) comprises a polarization splitter (3) which receives light pulses from the optical path (15) and from the optical delay line (14) and which is followed by a sensor body (2) which is traversed by the light pulses. A mirror (4) arranged on the side of the sensor body (2) on which the light is not incident reflects the light pulses back into the polarization splitter (3), which couples the light pulses back into the optical path (15) and the optical delay line (14).

Abstract: The yarn tension at each of a plurality of yarn processing stations is continuously monitored, while continuously determining the mean value of the monitored tension at each station, and while also continuously determining the differential between the monitored value and the mean value. Also, an alarm signal is generated whenever the mean value leaves a predetermined tolerance range, and whenever the differential value leaves a second predetermined tolerance range. An alarm signal may serve to actuate a visual error indicator, or to shut down the associated processing station.

Abstract: A method and apparatus to centrally collect measured values of a variable parameter from each of a plurality of work stations, and so as to facilitate quality control. Each work stations includes a sensor for generating an output signal which is a function of the variable parameter, and the output signal is converted to digital signals, which represent discrete increments within the measuring range of the variable parameter. The digital signals are stored during a predetermined period of time in a memory unit so as to be available for periodic scanning by the central computer, after which the stored signals are cleared so that the memory unit is free to record the values during the next period of time. Also, circuitry is provided whereby only the extreme values of the output signalsd ar stored, together with the mean value, which are adequate to provide a complete statement of the quality of the process and product being monitored.

Abstract: An optical movement sensor for clearly accurately detecting deformations of a human body. The movement sensor consists of a belt with a buckle made up of two parts which are joined together mechanically by a light-transmitting sensor element. Transmitting and a receiving fibre optic light guides are connected to one part of the buckle in such a way that light emitted by the transmitting light guide passes through the sensor element by way of a polarizer and is coupled to the receiving light guide via an analyzer.

Abstract: A pressure sensor comprises an optical system which is coupled to a diaphragm an which couples light emitted by a transmitting light guide into two receiving light guides depending on the deflection of the diaphragm. In order to enable the pressure values thus detected to be measured by means of a simple circuit, the transmitting light guide and the receiving light guides are arranged parallel to the diaphragm and the optical system is constructed as a focusing system, preferably a spherical lens arranged to be movable by the diaphragm 11 in a direction perpendicular to this diaphragm.

Abstract: An optical pressure sensor (1) is used for determining pressures and differential pressures of explosive liquids and gases and comprises a translucent body (2), having pressure measurement chambers (5, 7) formed as continuous holes. Sealing plates (3, 4), seal the pressure measurement chambers from the outside environment. The liquid or gaseous medium, introduced through inlet openings (9, 11) into the pressure measurement chambers and subjected to pressure, produces internal stresses in the body (2) so that the condition of polarization of polarized light (17), by which the body is irradiated, varies with the pressure in the pressure measurement chambers. An analyzer (18) filters from the light having a pressure-dependent condition of polarization linearly polarized light, whose intensity varies with the pressure of the medium to be determined. The pressure sensor is constructed in a simple manner and reacts with a high degree of sensitivity and accuracy to pressures and differential pressures.

Abstract: An optical transmission system arrangement for transmitting data between two relatively rotatable parts. A hollow cylinder with a mirror-coated inner surface onto which the light is incident at the smallest possible grazing angle and is frequently reflected. The light is coupled in and out through a coupling section in the hollow cylinder, at which the light is incident onto the inner surface. The system achieves a comparatively low damping because the reflecting power at small angles of incidence is comparatively high.

Abstract: A method and apparatus for producing a ribbon free randomly wound yarn package is disclosed, and wherein a plurality of critical winding ratios at which undesirable pattern formations or ribbons would normally occur are determined and stored in a microprocessor control unit. During the winding operation, the spindle speed and traversing frequency are monitored by sensors and are transmitted to the control unit, and the control unit computes the optimum time for rapidly changing the traversing frequency so that the actual winding ratio moves rapidly through each of the approaching critical winding ratios. The original traversing frequency is re-established after having passed beyond each of the critical winding ratios.

Abstract: A method and apparatus for winding textile yarns into core-supported packages is provided in which the formation of thickened and hardened places in the yarn packages at opposite ends thereof are avoided by a recurrent series of stroke modification cycles in which the length of traverse stroke is varied aperiodically as determined by a random number sequence. Additionally, the formation of undesirable patterns in the windings of yarn forming such packages is avoided by continuously varying the speed of traverse of the yarn guide by accelerating and decelerating the traversing yarn guide between predetermined maximum and minimum speeds. The stroke modification cycles and traverse motion speed changes are coordinated in such manner that the periods of high traverse motion speed coincide with the periods of short traverse stroke length and vice versa.