Abstract: A method for monitoring hydrogen gas and a hydrogen flame wherein an object light having a wavelength of about 309 nm and resulting from two or more laser beams, which have been irradiated to a space to be monitored, is collected and converted to an electronic image, and the electronic image is amplified and converted back to an optical image, thereby imaging a spatial intensity distribution of light at a specific wavelength. A device for monitoring hydrogen gas and a hydrogen flame, which comprises two or more laser beam sources, means for collecting an object light having a wavelength of about 309 nm and resulting from laser beams, which have been irradiated to a space to be monitored, image producing means for converting the object light to an electronic image, amplifying the electronic image, and converting back the amplified electronic image to an optical image, and means for imaging a spatial intensity distribution of light at a specific wavelength.

Abstract: A method for monitoring hydrogen gas and a hydrogen flame wherein an object light having a wavelength of about 309 nm and resulting from two or more laser beams, which have been irradiated to a space to be monitored, is collected and converted to an electronic image, and the electronic image is amplified and converted back to an optical image, thereby imaging a spatial intensity distribution of light at a specific wavelength. A device for monitoring hydrogen gas and a hydrogen flame, which comprises two or more laser beam sources, means for collecting an object light having a wavelength of about 309 nm and resulting from laser beams, which have been irradiated to a space to be monitored, image producing means for converting the object light to an electronic image, amplifying the electronic image, and converting back the amplified electronic image to an optical image, and means for imaging a spatial intensity distribution of light at a specific wavelength.

Abstract: A gas leakage monitoring method and system capable of ensuring safety of a gas utilization facility by visualizing invisible-to-naked-eye leakage gas and/or flame of leakage gas into the form of an image. The gas leakage monitoring method comprises the steps of collecting a detected light of a particular wavelength, which is caused by leakage gas and/or a flame of the leakage gas, in a space to be monitored, converting the detected light into an electronic image, amplifying and then converting the electronic image into an optical image again, and imaging the spatial intensity distribution of the particular wavelength light.

Abstract: A gas leakage monitoring method and system capable of ensuring safety of a gas utilization facility by visualizing invisible-to-naked-eye leakage gas and/or flame of leakage gas into the form of an image. The gas leakage monitoring method comprises the steps of collecting a detected light of a particular wavelength, which is caused by leakage gas and/or a flame of the leakage gas, in a space to be monitored, converting the detected light into an electronic image, amplifying and then converting the electronic image into an optical image again, and imaging the spatial intensity distribution of the particular wavelength light.

Abstract: In a common drive output circuit for driving dissimilar switching semiconductor devices having different drive input characteristics by turning on and off dc power supplies to apply a voltage between the drive input terminals of either one of the switching semiconductor devices through two transistors connected in a Darlington pair, the collector circuit of one of the two transistors which is not at the output stage has a diode inserted in series which has such a polarity as to permit passage of the collector current.

Abstract: A method of irradiating a metal piece (5) with a laser beam for generating a metal vapor (11) required for a metal vapor laser to oscillate. The method makes it possible to reduce the time required to activate the laser as well as the response time required to adjust the metal vapor density. Metals having a high melting point can also be vaporized for laser oscillation in accordance with the method.