Abstract: A method for analyzing the oxygen concentration of a gas with an oxygen concentration analyzer of such a type that a probe sensor, when supplied with a gas to be analyzed, produces an electrical output which is proportional to the concentration of oxygen in the gas, comprising the steps of preparing a first gas mixture in which an oxygen-free gas and a sample gas are mixed at a certain flow ratio and a second gas mixture in which the oxygen-free gas and the sample gas are mixed at a different flow ratio than in the first gas mixture, passing the first gas mixture and the second gas mixture asynchronously into the probe sensor, and comparing the electrical outputs from the sensor for the first gas mixture and the second gas mixture, as well as the proportions of the flow of the sample gas in the first gas mixture and the second gas mixture to thereby calculate the oxygen concentration in the sample gas.

Abstract: An atmospheric gas generator for heat treatment includes a heat treatment furnace for performing heat treatment of a metal material; an alcohol supply device for supplying alcohol to the heat treatment furnace; a nitrogen gas supply device for supplying nitrogen gas to the heat treatment furnace; and a nozzle having an end protruding into the heat treatment furnace. An atmospheric gas is generated by introducing the alcohol supplied by the alcohol supply device and the nitrogen gas supplied by the nitrogen gas supply device into the heat treatment furnace via the nozzle. The nozzle includes an alcohol introduction pipe, a nitrogen gas introduction pipe, and a venturi section provided in connection with a tip of the alcohol introduction pipe and with a tip of the nitrogen gas introduction pipe.

Abstract: The claimed invention provides an improved oxygen analyzer of the Hersch galvanic type that is suitable for measuring oxygen concentrations of 1 part per million (ppm) or less in a feed gas, as well as, methods of regulating said analyzer. Modifications have been made to the instrument, or its attendant supporting structures, that reduce or eliminate problems associated with the back flow of gas due to pressure differences between pipes for entrance and egress gases, problems associated with dead zones in the apparatus, or problems associated with dissolved oxygen present in water supplied to the detector. These problems have been addressed by modifying the instrument and its attendant structures, inter alia, to include a bypass pipe coupling between a pipe for gas supply to a detector and a pipe at gas outlet, including a check valve halfway between said bypass coupling, and providing means for detecting the pressure differential between a gas supply pipe and gas outlet pipe.

Abstract: A method of determining the dew point or frost point of a gas containing a very small amount of water uses an optical dew point meter having a reflector mirror the temperature of which can be varied from room temperature to any point of -80.degree. C. or below, a device for contacting the reflector mirror with the gas to be measured, a light source for irradiating the reflector mirror with focused rays of light, and a detector for detecting the change in scattered light and/or reflected light due to the dew and/or frost condensed on the reflector mirror. The method gradually reduces the temperature of the reflector mirror, either before or while the reflector mirror and the gas contact, thereby condensing dew and/or frost on the reflector mirror. Following formation of dew and/or frost on the reflector mirror, the intensity of scattered light or reflected light is adjusted from a maximum value to a constant level, at a controlled temperature.

Abstract: A method of measuring external leakage, which comprises the steps of introducing a first gas different from main component gasses of an external atmosphere into a pipe having a leak, adding H.sub.2 gas (or H.sub.2 -containing gas) to the first has at a down-stream point, and measuring gas components entering from the external atmosphere of the leak by an atmospheric ionization mass spectrometer (atmospheric pressure ionization mass spectrometer) at a further downstream point (for example, N.sub.2 H.sup.+ is detected when the external atmosphere is the N.sub.2 gas). A method of measuring the external leakage of a gas supply piping line having a plurality of branch piping lines comprises the steps of introducing H.sub.2 gas (or a H.sub.

Abstract: A welding method for forming an oxide passivation film having corrosion resistance and an extremely small emission quantity of an outgas during welding at a weld portion and portions nearby, and a process apparatus requiring an ultrahigh-clean atmosphere. A back-shielding gas comprising an inert gas containing 1 ppb to 50 ppm of oxygen gas is caused to flow during a welding process, and an oxide passivation film comprising chromium oxide as a principal component is formed on the surface of the weld portion. In a process apparatus using welding for installing the apparatus, a back-shielding gas comprising an inert gas containing 1 ppb to 50 ppm of oxygen gas is caused to flow during a welding process and an oxide passivation film comprising chromium oxide as a principal component is formed on the surface of a weld portion.

Abstract: The invention relates to an apparatus for determining the frost point of a gas containing a very small amount of water. The apparatus comprises (I) compartment A made of a good heat conductor; (II) an inlet for the gas to be measured, which inlet is provided on compartment A; and (III) a heater for adjusting the temperature in compartment A, and a temperature sensor. The apparatus further comprises (IV) compartment B which is adjacent to compartment A. At least part of compartment B is made of a poor heat conductor. Further, the apparatus comprises (V) a hole at the interface between compartments A and B and (VI) a reflector mirror having a temperature sensor. The reflector mirror is provided on compartment B in such a way as to cover the hole is connected thermally to a freeze source in such a way that the temperature of the reflector mirror can be varied from room temperature to at least -80.degree. C.

Abstract: A method of determining the dew point of a gas containing a very small amount of water using (1) a reflector mirror the temperature of which can be varied from room temperature down to at least -80.degree. C.; (2) a source of condensed rays of light for irradiating the reflector mirror; and (3) a light recovering device that detects changes in scattered light due to condensation on the reflector mirror by exposing the mirror to the gas. The method comprises cooling the mirror and detecting the temperature at which the scattered light has a maximum intensity; slowly raising the temperature and detecting the temperature at which the scattered light has a minimum intensity and repeating the cycle until the temperature at which the intensity is a maximum and the temperature at which the intensity is a minimum are almost the same.

Abstract: A method of cleaning a reflector mirror in an optical dew point meter that measures the dew point or frost point of a sample gas by a process including the steps of bringing the sample gas into contact with the reflector mirror whose temperature is variable, projecting condensed rays of light or laser light onto said reflector mirror, and detecting the change in the intensity of scattered light and/or reflected light on account of the dew or frost formed on said reflector mirror, characterized by bringing a CO.sub.2 gas or a CO.sub.2 containing gas into contact with the reflector while the latter is in a cooled state, thereby condensing CO.sub.2 on the surface of the reflector mirror, and the subsequent step of heating the reflector mirror to vaporize the CO.sub.2 is dischosed.

Abstract: A process for a passivated film which is far reduced in the amount of gas discharge and can desorb an adsorbed gas more readily, which process comprises heating a stainless member with a surface roughness, Rmax, of 1.0 .mu.m or less in an atmosphere of a mixture comprising oxygen gas and an inert gas and having a dew point of -95.degree. C. or below, an impurity concentration of 10 ppb or less and an oxygen content 5 ppm 25 vol % at 300.degree. to 420.degree. C.

Abstract: A probe having the inventive composition, it is possible to measure the activity of the solute carbon which could not be measured by the prior art because there did not exist solid oxide or solid composite oxide which were stable at high temperature.The probe comprises a solid electrolyte having a mixed subelectrode provided on its surface, and a reference electrode for providing a predetermined oxygen potential is disclosed. The mixed sub-electrode coating on the solid electrolyte includes a mixture of a carbide MC and of an oxide MO of the element M other than carbon of which the carbide is constituted.

Abstract: An apparatus for forming a resin coating on the surface of an article having a three-dimensional structure, comprising: (i) a compartment (a) in which the surface of the article is coated with a resin solution, (ii) a compartment (b) in which said resin solution coated on said article is cured; and (iii) means for successively transporting said article through said compartments; wherein said compartment (b) is substantially shut off from the outside air and has an entrance and an exit for said article transport means, said entrance and said exit being provided with respect guide members having substantially the same cross-sectional configuration.

Abstract: A method of soldering for surface mounting of a printed circuit board, which comprises performing reflow soldering with a rosin-based cream solder in a special atmospheric gas comprising an inert gas such as N.sub.2, Ar or He and containing about 10,000 ppm or less of oxygen and 0.5-3.0% of moisture is disclosed.

Abstract: An improved method of and an apparatus for measuring a very low water content in a non-condensible gas which has a dew point in the range of from ordinary temperature to -80.degree. C. or less. The gas to be measured is pre-cooled to a temperature slightly higher than that of the dew point, and is then blown against a reflecting mirror whose surface is cooled down to the dew point temperature of the gas. A condensed light having high luminance is projected toward the reflecting mirror. When the gas is blown against the mirror and cooled down to the temperature of the dew point, thereof a dew or frost is formed on the mirror, and the amount of scattered light reflected from the mirror is increased by the dew or frost. This increase in scattered light is detected by a photodetector. A silicon wafer which is polished to have a surface precision of 1/4 or less that of the wavelength of the condensed light is employed as the mirror to enable measurement of dew points of -80.degree. C. or less.

Abstract: An improved oxygen analyzer device is disclosed which comprises a gas flow passage having inlet and exhaust ports, an oxygen concentration detector in proximity to the exhaust port and first and second parallel intermediate flow passages, one of which contains a purifier to remove oxygen from the gas flowing therethrough. The device is characterized by the use of metal, diaphram-type, three-way valves in the branch-off and junction points between the intermediate flow passages. The valves eliminate dead space in conventional devices that extends both the calibration and analysis time of such devices.

Abstract: A probe for measuring the concentration of an impurity in molten iron is disclosed. The probe comprises three sensors. The first sensor measures the activity of the impurity element directly. The second sensor measures the activity of free oxygen. The third sensor measures carbon content. These values are used are used to give a compensated measure of the impurity element.

Abstract: A process for separating enriched oxygen and argon from air through pressure swing adorption by using an adsorbent which is capable of selectively adsorbing nitrogen. Product gas is recovered from one adsorption column in which the adsorption step has already been completed by moving the gas to another adsorption column in which regeneration of the adsorbent by pressurization with the product gas has already been completed on the basis of pressure equalization. In this case, at the same time as the gas is being moved from the feed end of one column to the feed end of another, the gas may also be moved from the effluent end of the former to the effluent end of the latter. In this way, it is possible to stably and readily obtain an enriched oxygen gas having a lowered nitrogen content at an increased specific product and a lowered specific power consumption.

Abstract: There is provided an improved process for forming high purity carbon monoxide wherein a product of substantially uniform purity is obtained. A waste gas containing at least CO, CO.sub.2 and N.sub.2 is treated by pressure swing adsorption in two stages to remove CO.sub.2 and CO, respectively. The CO content of at least the feed gas and the second stage product gas are monitored and an amount of second stage product gas is recycled to the feed gas and/or the first stage product gas sufficient to assure substantially uniform CO content in the second stage product gas withdrawn from the system.

Abstract: A process for separating carbon monoxide from a feed gas comprising CO.sub.2, CO and less adsorbable component than CO through PSA by using at least two adsorption columns in two stage adsorption operation which comprises a first adsorption stage for removing CO.sub.

Abstract: A process for separating carbon monoxide from a feed gas .[.comprising.]. .Iadd.including .Iaddend.CO.sub.2, CO and less adsorbable component than CO through PSA by using at least two adsorption columns in two stage adsorption operation which .[.comprises.]. .Iadd.includes .Iaddend.a first adsorption stage for removing CO.sub.2 from .[.said.]. .Iadd.the .Iaddend.feed gas and a second adsorption stage for separating CO from gaseous mixture withdrawn from the first adsorption stage:(1) the first adsorption stage comprising a pressure swing adsorption repeating adsorption and desorption, and(2) the second adsorption stage comprising:(i) pressurization by the first stage product gas,(ii) adsorption,(iii) depressurization,(iv) purge by product gas,(v) evacuation for recovering product gas, and(vi) pressurization by gas withdrawn in other column, periodically switching the flow between or among .[.said.]. .Iadd.the .Iaddend.