Abstract: A method detects incomplete coverage of hermetic coatings applied to opti fibers during in-line optical fiber fabrication procedures as well as off-line applications. A fluorescent material surrounds the core region of the optical fiber prior to the formation of the hermetic coating on the optical fiber and energy is radiated in the optical fiber to propagate in the cladding mode. This causes an excitation of the fluorescent material to fluoresce in response to the propagated energy. An appropriately disposed detector detects levels of emitted fluorescence along the length of the optical fiber to indicate where the hermetic coating is incomplete or where pinholes in the hermetic coating are located. Optionally, the fluorescent material is located outside of the cladding layer, inside of the cladding layer near its outer surface or throughout the cladding region to fluoresce when excited by the propagated energy.

Abstract: An infrared paper web moisture sensor is described which comprises a source of infrared radiation for directing an infrared beam through the web and an infrared detecting unit disposed on the opposite side of the web from the infrared source. In one embodiment, the infrared detecting unit measures the transmission of the infrared beam through the web at three separate wavelength regions of the infrared spectrum, one of which is sensitive to web temperature. In a second embodiment, the infrared detecting unit measures the transmission of the infrared beam through the web at two separate wavelength regions of the infrared spectrum, one of which is insensitive to web temperature. For each embodiment, signals are developed indicative of the transmission of infrared through the web in each of these regions, digitized, and fed to the process control computer for the paper mill.

Abstract: What is disclosed is a preamplier used with each pyroelectric detector in an infrared imaging array system. To construct each preamplifier and an associated detector in a dense detector array, solid state manufacturing techniques are utilized. To bias the preamplifier either a high bias impedance is effectively provided by doping the material from which the detector is made; or a MOSFET bias switch is provided that is periodically operated to place charge on the gate of the preamplifier transistor to maintain it at its bias level. When the bias switch is not operated, the associated detector detects and a reading is taken from each detector in the array.

Abstract: A non-dispersive infrared gas analyzer of the type typically used to measure concentrations of gases in medical and industrial applications has no moving parts and employs two or more miniature infrared sources ("microsources") which are electrical current-modulated to produce modulated infrared radiation for synchronous detection. The microsources are operated at different frequencies. The frequency-multiplexed detector signal is demodulated and ratioed to yield an output which is correlated to the gas concentration in the sampler chamber.

Abstract: A radiation image recording, read-out and reproducing apparatus comprises a system for circulating and conveying stimulable phosphor sheets, a section for feeding recording sheets, a section for recording a radiation image on the stimulable phosphor sheet, a scanning section, an erasing section, and a system for conveying the recording sheet from the recording sheet feeding section to the scanning section and then out of the scanning section. The scanning section comprises a read-out main scanning system for scanning light in a main scanning direction on the stimulable phosphor sheet, a reproducing main scanning system for scanning light in the main scanning direction on the recording sheet, and a sub-scanning system for moving the stimulable phosphor sheet and the recording sheet in a sub-scanning direction, thereby to carry out both the image read-out from the stimulable phosphor sheet and the image reproduction on the recording sheet.

Abstract: What is disclosed is a preamplifier used with each pyroelectric detector in an infrared imaging array system. The preamplifier transistor is a MOSFET transistor that can operate with zero volts between its source and gate terminals, and the preamplifier is biased either by a nonconducting diode that provides a high biasing impedance while the bias voltage is low enough to keep the diode below its conduction voltage; or an NPN transistor switch is periodically operated to place charge on the gate of the preamplifier transistor to maintain it at its bias level. When the bias transistor is not operated, the associated detector detects and a detector reading is taken from each detector in the array. NPN transistor switches can be manufactured consistently and their conduction level can be adjusted to balance the gain of all preamplifiers in the detector array.

Abstract: A light beam containing at least ultraviolet light in a predetermined wave range is projected onto a portion of a floppy disk casing applied with a liner, and ultraviolet light in the predetermined wave range contained in reflected light from each point on the portion of the casing is received. The intensity of the received ultraviolet light corresponding to each point is subjected to a threshold processing and whether the liner is applied to the inner surface of the casing in a satisfactory state is determined on the basis of the result of the threshold processing.

Abstract: A dosimeter for ionizing radiation is of oblong shape. It comprises a gas-filled measuring chamber surrounded by a casing. THe casing is formed of two oblong frames of insulating material that are substantially similar in shape. The two frames are mounted on each other in a gas-tight manner. The anode wires are situated in the plane of separation between the frames and are secured by the frames in contact with each other. At least one of the frames is provided with a cathode over its whole length and parallel to the plane in which the anode wires are situated. Along the edge of the cathode extends a guard electrode which surrounds the cathode with a certain gap. The dosimeter is made of materials that are transparant to the ionizing radiation. It can be used particularly in slit radiography equipment in which the slitwidth can be controlled locally and independently along the length of the slit.

Abstract: A method and apparatus for inducing fluorescence in human skin, in vivo, and for evaluating certain skin characteristics from the spectral intensity of induced fluorescence. The energy of a helium-cadmium laser is directed to a skin area to be evaluated by a fiberoptic element. The induced fluorescent energy having a wavelength band of interest above that of the laser wavelength, is directed to a device by a fiberoptic path for performing a spectral analysis of the fluorescent intensity. A ratio of chracteristic portions of fluorescent intensity of the skin area under test is developed and used to compare with different test subjects. The developed ratio, when taken in relation to the skin of subjects of different ages, indicates a marked difference in older subjects in comparison to that of very young subjects which correlates with long-term exposure of the skin to ultraviolet radiation.

Abstract: A radiation detecting circuit includes a semiconductor radiation detector, a charge converting circuit, a duration time measuring circuit, an incident position detecting circuit, and a correcting circuit, A photon is detected by the detector, and charges are induced therein. Based upon these charges, the duration time period of induction current is measured, and the positional signal of the incident photon is produced based upon the duration time period of the incident photon. The voltage output from the charge converting circuit is corrected on the basis of the positional signal so as to produce an energy value of the incident photon independent of the incident position on the detector.

Abstract: A detector for counting low levels of photons comprises a plurality of thin solid state wafers of a photons sensitive material such as gallium arsenide; the wafers being of the order of one-tenth to two millimeter thick depending upon use, and providing a depletion layer of 2 to 20 millimeters deep depending upon the energy of the photons to be detected. The electrical length of the wafer depends upon the use for which the panel is designed and may be one-tenth to two millimeters if two dimensional analysis is desired. Some of the wafers depending upon their materials have a region beyond the 2 to 20 millimeter depth in which is formed an integrated circuit including a detector, preamplifier, discriminator, scaler and read out buffer, each responsive to a different multiplexed, digitized address word. The wafers are connected as PIN diodes and are properly biased for such function. Those wafers using materials on which IC cannot be formed are connected to ICs by leads.

Abstract: A system for detecting ultra-violet radiation has a cold cathode discharge tube which produces a pulse each time it avalanches. A logic arrangement steers these pulses successively to separate timers in that order. In response to each pulse, each timer sends its own output line HIGH for a preset period, the same for all the timers. An AND gate receives all the timer outputs and produces an alarm signal when all these are HIGH at the same time.

Abstract: Shading is eliminated in an image read-out apparatus for scanning a light beam on a recording medium carrying an image recorded thereon, obtaining light which carries the image by the scanning, and detecting the light by use of a photomultiplier to obtain read-out signals carrying the image. A shading elimination method comprises the steps of detecting the shading characteristics in the direction of main scanning of the light beam by changing the level of high voltage applied to the photomultiplier to a plurality of levels prior to the detection of the light, and storing the shading characteristics to correspond to the levels of the high voltage in a memory. The level of the high voltage is detected at the time of the detection of the light, and the shading characteristics that correspond to the detected level of the high voltage are read from the memory.

Abstract: A radiation image recording and read-out apparatus comprises a read-out and erasing unit provided with an image read-out device for irradiating stimulating rays to an image-recorded stimulable phosphor sheet and detecting light emitted by the stimulable phosphor sheet upon exposure to stimulating rays, and a device for erasing radiation energy remaining on the stimulable phosphor sheet. The read-out and erasing unit is reciprocated normal to the direction of irradiation of stimulating rays for carrying out image read-out during forward movement, and carrying out erasing by the erasing device during backward movement.

Abstract: An optical filter and detector, and a related method for its operation, in which signal photons are admitted into a detector cell and selectively excite atoms or molecules of a vapor to a selected metastable state. An illuminating laser then photoionizes a large proportion of the excited atoms or molecules, and the resulting free electrons are collected as a measure of the number of incident signal photons. The initial excitation step to a metastable state is highly sensitive to the wavelength of the signal photons and therefore acts as a narrowband filter.

Abstract: Method and apparatus for detecting and differentiating organic compounds based on their electron affinity. An electron capture detector cell (ECD) is operated in a plurality of multiplexed electroncially programmable operating modes to alter the detector response during a single sampling cycle to acquire multiple simultaneous chromatograms corresponding to each of the different operating modes. The cell is held at a constant subatmospheric pressure while the electron collection bias voltage applied to the cell is modulated electronically to allow acquisition of multiple chromatograms for a single sample elution from a chromatograph representing three distinctly different response modes.

Abstract: The dielectric layers which sandwich the fluorescent layer therebetween are formed of amorphous SiYON or SiYAl ON. These layers exhibit improved adhesive characteristics and attenuate interlayer separation during production and under prolonged voltage impression.

Abstract: The present invention relates to an improvement in a nuclear measuring gauge for measuring the composition of a hydrogen containing material by counting neutrons which are thermalized by the presence of the hydrogen in the material. The present invention is based upon the recognition that in measuring samples, such as hot asphalt, with such a gauge, the error which is introduced by temperature variations in a sample is a function of not only the temperature of the sample but also its hydrogen content. In accordance with the present invention, this inaccuracy is compensated for by applying to the measurement a correction factor which is a function of both the temperature of the sample and its hydrogen content.

Abstract: A radiation image read-out apparatus comprises a stimulating ray source for producing stimulating rays which excite a stimulable phosphor, a device for scanning the stimulating rays on a stimulable phosphor sheet carrying a radiation image stored thereon in a main scanning direction, and a fluorescent light guide member obtained by forming a sheet-shaped material containing a phosphor and disposed so that a surface of the fluorescent light guide member receives the light emitted by the stimulable phosphor sheet when the stimulable phosphor sheet is scanned by the stimulating rays. A photodetector is closely contacted with an end face of the fluorescent light guide member, and a sub-scanning device is provided for moving the stimulable phosphor sheet with respect to the stimulating rays in a sub-scanning direction approximately normal to the main scanning direction.

Abstract: A low-cost radon detector using a solid state diode having a depletion layer disposed close enough to a test medium that alpha particles deposit their energy in the depletion layer. The signal produced by the diode is amplified and pulses are discriminated for levels over a threshold typical of pulse levels produced by radioactive decay of radon daughters on the surface of the sensor. More than one amplifier and threshold detector are provided, and the sensor can have plural solid state diodes. Pulses occurring exclusively on one channel are counted and pulses occurring in coincidence on more than one channel are ignored as instances of transient disturbance. A conductive enclosure around the sensor element can be biased to force radon daughter ions to plate out the sensor, whereupon decay of the daughters produces pulses falling closely into pulse height ranges well above the noise threshold. Pulse counts and time lapse are monitored both long term and short term.