Abstract: A fast response output signal circuit (10) for a cold cathode gauge is provided to produce a fast response output signal (48) in addition to a voltage output signal (40) that is representative of the pressure in the cold cathode gauge. The fast response output signal (48) is either on or off, thus can be used to trigger a closing of an isolation valve or other responsive action upon a change in pressure that attains or exceeds a certain set point threshold. The fast response output signal is produced and processed with analog circuits, but the set point is produced with a microprocessor. The voltage output signal can be produced as a logarithmic function of the pressure.

Abstract: A technique for reducing an electromagnetic noise entering an electrode or a drift of a signal due to a fluctuation in the ambient temperature is provided to improve the S/N ratio of a signal originating from a component of interest. A dummy electrode having the same structure as an ion-collecting electrode is provided within a lower gas passage at a position where dilution gas with no sample gas mixed therein flows. A differential amplifier is provided to perform differential detection between output A of a current amplifier connected to the ion-collecting electrode and output B of a current amplifier connected to the dummy electrode. The differential signal is free from a common mode noise or drift and hence accurately reflects the amount of the component of interest.

Abstract: There is provided a fine particle detection system with a fine particle sensor, a cable and a sensor drive control device. The fine particle sensor has an ion source unit with first and second electrodes, a particle charging unit and inner and outer sensor casings. The cable has a power supply wiring line connected to the second electrode, an inner shield line electrically continuous with the inner sensor casing and an outer shield line electrically continuous with the outer sensor casing. The sensor drive control device has an ion-source power supply circuit, a signal current detection circuit, an inner circuit casing electrically continuous with a first output terminal of the ion-source power supply circuit and surrounding the ion-source power supply circuit and an outer circuit casing connected to the ground potential and shielding the ion-source power supply circuit, the signal current detection circuit and the inner circuit casing.

Abstract: A discharge ionization current detector using a low-frequency barrier discharge is provided to improve the linearity of detection sensitivity with respect to a sample introduction amount. From a lower end of a lower gas passage connected to a lower end of an upper gas passage, a dilution gas is supplied upward against a downward flow of a plasma gas. A gas discharge passage for discharging a plasma gas, the dilution gas and a sample gas is arranged between an ion-collecting electrode and a bias voltage application electrode. The sample gas introduced through a capillary tube is mixed with the plasma gas and the dilution gas due to a disturbed flow generated by collision of the plasma gas and the dilution gas. The sample component is efficiently ionized by light from the plasma without undergoing light-shielding effect of concentrated sample components.

Abstract: An ionization gauge to measure pressure and to reduce sputtering yields includes at least one electron source that generates electrons. The ionization gauge also includes a collector electrode that collects ions formed by the collisions between the electrons and gas molecules. The ionization gauge also includes an anode. An anode bias voltage relative to a bias voltage of a collector electrode is configured to switch at a predetermined pressure to decrease a yield of sputtering collisions.

Abstract: The invention relates to a device for checking the operability of a sensor element (100) for determining the concentration of gas components in a gas mixture, particularly of the concentration of gas components in the exhaust gas of internal combustion engine, having an external pump electrode (APE) and an internal pump and Nernst electrode (IPE), a measurement resistor (Rm) and a balancing resistor (Rtrim) connected parallel thereto being provided upstream of the external pump electrode (APE), and a pump current (Ip) being impressible into the external pump electrode by means of a pump current source, and a measuring voltage (Um) incident across the measuring resistor (Rm) via a measuring and analysis device (200) being detectable, characterized in that an activatable switch means (S) is disposed in series to the measuring resistor (Rm), which can be switched at a high impedance for a predetermined amount of time, during which the voltage across the measuring resistor is detected and analyzed in the measurin

Abstract: It is intended to realize measuring of trace organic components and to render qualitative procedure efficient through imparting of selectivity. Penning gas and dopant gas are ionized in a space isolated from discharge part with the use of metastable helium obtained by direct-current glow discharge, and with the use of thus obtained plasma, the efficiency of ionization of components to be measured is enhanced, so that intensified ion current can be obtained. Further, through selection of dopant gas and Penning gas, selectivity can be imparted. Thus, not only can measuring of trace organic components be performed but also selectivity can be imparted.

Abstract: Detecting air ingredients is obtained, a heater and gas sensitive acting layers are arranged on a substrate, which are connectable to an analyzing unit. Electrical resistances of n acting layers are connected in series; heater is a temperature sensor connected in parallel with this series connection, electrical resistance of heater is smaller than the sum of electrical resistances of acting layers and resistances are connected with a total of n+1 electrical terminals via electrodes so that heater is connected with two terminals and n?1 other terminals are connected with a respective junction that interconnects two acting layers. Heater is intermittently heated so that a predefined constant temperature of acting layers is achieved, temperature of acting layers is acquired by determining electrical resistance of heater; voltages in the series connection of acting layers are analyzed and a concentration of gases are determined from electrical resistances of acting layers.

Abstract: A gas concentration detection apparatus includes a series-connected combination of a sensor element and a resistor, with an AC voltage being applied to one of the outer terminals of that combination and with the other outer terminal being held at a fixed potential. A DC voltage signal at a level determined by an oxygen concentration that is detected by the sensor element, and an AC voltage signal at an amplitude determined by sensor element impedance and hence by the sensor element activation status, are extracted from the series-connected combination by respectively separate circuits which apply separately determined amplification factors.

Abstract: A process module tuning method characterizes a process module by gathering data using a process condition measuring device to measure process outputs while inputs are excited. The data is used to identify a dynamic process model. The dynamic process model is then be used to determine process input settings that will produce desired outputs. For multi-zone process modules, the interactions between zones may be modeled.

Abstract: A sensor having a nanotube grown on and supported by thermal bimorph structures. The nanotube rests on a heat sink during sensing gas or a liquid and is moved from the heat sink when the nanotube is heated to desorb gas or liquid from it. The heatsink may function as a gate along with the bimorph structures as the other terminals of a transistor. Current-voltage and current-gate voltage characteristics may be obtained of the nanotube as a device like a transistor. These characteristics may provide information on a gas or liquid absorbed by the nanotube.

Abstract: A sensor having a nanotube grown on and supported by thermal bimorph structures. The nanotube rests on a heat sink during sensing gas or a liquid and is moved from the heat sink when the nanotube is heated to desorb gas or liquid from it. The heatsink may function as a gate along with the bimorph structures as the other terminals of a transistor. Current-voltage and current-gate voltage characteristics may be obtained of the nanotube as a device like a transistor. These characteristics may provide information on a gas or liquid absorbed by the nanotube.

Abstract: Disclosed is a portable gas alarm device easy to be fabricated as a small-sized one handy to carry and high in convenience for use. The portable gas alarm device comprises a gas alarm device body having a casing flat in whole and a fitting member provided on the casing to fit it to the human body. The gas alarm device body has a control circuit board extending to the direction of the flat plane of the casing, a display mechanism is arranged in a central area on the front surface side of the control circuit board, a gas sensor and an alarm buzzer are arranged on the right and left sides of the display mechanism, and a battery fitting chamber is provided on the back surface side of the circuit board. A vibration generator for alarm may be provided in the gas alarm device body. The fitting member may be one suitable for use in fitting the gas alarm device body to a person's wrist or a person's wear.

Abstract: An aerosol detector, particularly well suited for liquid chromatography applications, includes a corona discharge source controlled to selectively charge the non-volatile residue particles of an aerosol. The aerosol initially is composed of droplets of a liquid sample, with the residue particles resulting from droplet evaporation. The selectively charged residue particles, each carrying a charge in proportion to its size, are collected at a conductive filter. The electrical current along a conductor coupled to the filter is measured repeatedly or continuously to provide an indication of concentrations of the non-volatile material. Preferably, a pneumatic nebulizer is used to generate the aerosol. When used in a liquid chromatography system, the detector can yield several separated areas of relatively high electrical current, corresponding to concentrations of several different analytes in the liquid sample.

Abstract: There are provided a test apparatus and a test method for testing a semiconductor integrated circuit which facilitate control of a BOST device and improve the versatility of the BOST device. There is provided an interface for exchanging signals between a BOST device and an external controller. A test control signal and a test result analysis signal are exchanged by means of the interface, thus effecting a test and analysis of the test.

Abstract: The present invention is a method by which the deterioration judgement and the correction of an electrochemical carbon monoxide gas sensor are simply carried out without using the correction gas. The method of the present invention is that: the voltage is applied from the outside so that the working electrode of the electrochemical carbon monoxide gas sensor is operated as the negative electrode, and the counter electrode is operated as the positive electrode, and hydrogen is generated from the working electrode, and oxygen is generated from the counter electrode; after that, the potential of the working electrode and the counter electrode is returned to the operation potential as the sensor; and by using the reaction on the hydrogen remained in the vicinity of the working electrode, the sensor current is generated, thereby, it is tested whether the sensor is normally operated.

Abstract: In a discharge ionization detector, a method and apparatus are disclosed for increasing the transfer of photons and metastables from a discharge chamber to a ionization chamber, while effecting ion discrimination of the ionic current with respect to a signal cathode, thereby reducing the effect of ionic current in the signal output. Preferred embodiments of the invention include a discharge source located in a discharge chamber, means for introducing discharge gas flow into the discharge chamber, a flow guide that directs discharge gas flow between the discharge chamber and an adjacent ionization chamber, and inlet port for introducing a flow of sample gas containing an analyte into the ionization chamber and an outlet port for exhausting the sample gas and the discharge gas. A plurality of apertures in the flow guide are situated proximate the discharge source so as to promote the rapid and efficient transfer of photons and metastables from the discharge source into the ionization chamber.

Abstract: Electron capture detector for use with an effluent stream from a gas chromatograph includes an electron source means and an adjacent ionization chamber in which electron capture takes place. The active region of the ionization chamber is disposed to receive free electrons and a flow of purge gas. The detector has an inlet port for receiving a sample gas as well as an outlet port for exhausting the sample gas and the purge gas. A collector electrode in the detection chamber is biased so as to collect the free electrons in the absence of electrophilic substance. Electrophilic substances in the detector will reduce the flow of electrons to the collector and generate an ionic current. An insulative member in the form of a flow guide may be located at the portion of the anode so as to permit pulsing of free electrons to the anode but substantially block the ionic current, i.e., to discriminate between the free electrons and the ionic current.

Abstract: Apparatus for detecting an electronegative species comprises an analysis chamber, an inlet communicating with the analysis chamber for admitting a sample containing the electronegative species and an ionizable component, a radioactive source within the analysis chamber for emitting radioactive energy for ionizing a component of the sample, a proportional electron detector within the analysis chamber for detecting electrons emitted from the ionized component, and a circuit for measuring the electrons and determining the presence of the electronegative species by detecting a reduction in the number of available electrons due to capture of electrons by the electronegative species.

Abstract: An improved photoionization detector has a sweep gas inlet which is used to introduce sweep gas near the window of the detector's ultraviolet lamp. The detector's chamber has a vent which allows selective removal of spurious analyte. The detector is adapted to have directly mounted on it, a second detector. Sweep gas used to keep analyte away from the window may be used as a reagent in the second detector. In addition, a means for regulating the ionization lamp voltage is disclosed which prolongs lamp life expectancy.

Abstract: A detecting element (6) comprising a solid zirconia electrolyte (6a), a reference electrode (6d), a detecting electrode (6c) and a diffusion member (6a) is provided, and also a driving circuit (1b, 4) for impressing a voltage between the electrodes (6c, 6d) of said detecting element so as to detect the threshold current of an oxygen ion pumping current (I.sub.p) is provided. The output of this driving circuit is delivered as a continuous output (V.sub.o) of an air fuel ratio of fuel gas comprising al the regions of rich, stoichiometric and lean air fuel ratios. On the other hand, an I.sub.p detection resistor (Rs) for detecting the pumping current flowing between the input/output terminals of the driving circuit is provided. The opposite-end voltages (V.sub.a, V.sub.o) of this I.sub.p detection resistor are compared by a comparator (5), and a step signal corresponding to the stiochiometric air fuel ratio (.lambda.) is outputted from this comparator.

Abstract: A small volume electron capture detector has a cylindrical cell 120 inside which there is provided a generally funnel-shaped insert structure 130 having a cup-shaped section and a cylindrical section. The rims of the cup-shaped section nearly touch the inner walls of the cell 120 so as to separate the active volume from the areas at the top corners of the cell 120 which are not actively swept by the carrier gas, thus reducing the tailing of chromatographic peaks.

Abstract: An electron capture detector for use with a capillary column is provided with a sample inlet comprising a tubular anode through which sample molecules and a make-up gas are introduced into the detector cell. The tubular anode has side ports for producing a plug-like flow inside the cell. The inner surface of the anode is protected by an insulating tube so that the capillary column can be extended to a point beyond the side ports without the fear of its electrical contact with the anode. This allows the sample molecules to flow nearly entirely in the center section of the cell. The peripheral regions of the cell where a radioactive foil is disposed is swept nearly entirely by the make-up gas entering the cell through the side ports. This has the effects of reducing sample dilution by the make-up gas and sample loss due to contact with the detector walls.

Abstract: A gas discharge tube is provided for use in a detector of the type capable of identifying ionizable species in a carrier gas. The tube contains an inert gas at reduced pressure and the gas is excited by an external circuit including a coil about the tube. The circuit generates a radio frequency which excites the gas and emits ultraviolet radiation. This radiation passes through a transversely located window at the end of the tube for ionizing the species in a chamber. Electrodes are also described for use in association with the chamber to sense ionization. These electrodes form part of a sensing circuit.

Abstract: To guide gas to the electrode of a high temperature sensor, a substrate (1), for example of ceramic or ceramic-coated metal has electrodes (3, 4; 7, 8; 16, 17) applied thereto, for example in meander pattern, spaced from each other. A heater is applied to the substrate, either on the same side (FIGS. 2, 3) or on the backside (FIG. 1). Gas is guided to the electrodes by projecting ridges and posts (11, 12) to thereby prevent fouling of the electrodes by gas; the ridges and posts, additionally, can be protected by a cover (18) FIG. 3, thereover. The spacing 13 between the ridges and posts, and the cover, if provided, is so arranged that resonance chambers are formed which are resonant at the expected frequencies of, for example, engine knocking or unusual combustion conditions.

Abstract: An electron capture detector in which a thermionic source such as a filament provides electrons for the reaction in a source chamber having a port that connects to a detection chamber having a collector. Guard gas is introduced into the source chamber and sample gas into the detection chamber, and an exhaust port is provided in the detection chamber.

Abstract: An electron capture detector in which electrons for the reaction are supplied by a filament in a cylinder through which guard gas is passed. Apertures in the cylinder permit electrons from the filament to pass into an annular space surrounding the cylinder and between it and a collector. Sample gas is passed between the aperture and the collector, the pressures being such as to be capable of minimizing the diffusion of sample gas to the filament.