Abstract: The conduit tube 3 and the conduit tube 4 to flow the carrier solution to the gas exchanger 7 are provided, and in the conduit tube 3, the reference pH electrode 14 is provided, and in the conduit tube 4, the measuring pH electrode 16 is provided. The gas exchanger 7 is partitioned from the outside by the gas permeable membrane 6. Initially, the gas exchange section 1 is inserted into the test substance, and next, the carrier solution is flowed at the speed of a degree in which the gas exchange is not conducted in the gas exchanger 7. The output potential difference &Dgr;V(0) between the reference pH electrode 14 and the measuring pH electrode 16 at this time, is found.

Abstract: A biological gas sensor for measuring a carbon dioxide partial pressure in an alimentary canal while excluding the influences of hydrogen sulfide and/or weak acid is disclosed. The gas sensor comprises a sensor which has in the sensitive part thereof a bicarbonate buffer solution held by a gas permeable membrane and detects a carbon dioxide partial pressure based on the hydrogen ion concentration of the bicarbonate buffer solution, a liquid holding part which is formed of a gas permeable tube having in the inside thereof the sensitive part of the sensor, an isotonic solution which is held in the liquid holding part and is isotonic with the bicarbonate buffer solution, and a metallic member (e.g., a coil of copper wire) so that hydrogen sulfide entering the liquid holding part may react with the metal and precipitate.

Abstract: A gas sensor 1 has a catheter 3 to which a gas sensor body 4 and a signal guide member 5 for guiding a detection signal of the gas sensor body 4 are attached. The other end of the signal guide member 5 is connected to a connector 6. The gas sensor 1 is airtightly received in the reception body in the state where a connection terminal of the connector 6 is exposed to the outside. The reception body 2 is filled with a mixed gas containing a gas to be measured by a predetermined concentration. At the time of calibration, the connection terminal of the connector 6 is connected to a measurement amplifier while the reception body 2 is not opened and calibration is performed, and at the time of measurement, the reception body 2 is opened and the gas sensor 1 is taken out to perform ordinary measurement.

Abstract: There is disclosed an apparatus for the determination of a trace amount of an analyte substance or organism. A substrate solution is brought into contact with a small diameter tube which has captured, at least on its inner surface, a trace amount of an analyte substance or organism. The trace amount has the ability to change the pH of the substrate solution.

Abstract: A method for assaying an enzyme on a targeted solid body surface, including the steps of contacting an end opening of a thin tube with a targeted solid body surface to form a space between the targeted solid body surface and inner wall surface of the thin tube, supplying a substrate solution into the space to bring the substrate solution in contact with the targeted solid body surface, and determining a pH change of the substrate solution in the space by using a pH electrode; and an apparatus therefor.

Abstract: A method for measuring trace amounts of analyte substance(s), which utilize a pH electrode is disclosed. This method is by far simpler than conventional optical detecting systems. The apparatus for practicing the method is also disclosed. By the use of pH electrode, the apparatus is compact, inexpensive and easy to operate, and hence usable in small-size and medium-size hospitals or clinical laboratories and by patient's bedside.

Abstract: A blood component monitoring system for monitoring chemical substances of interest in blood, which includes a transfusion circuit including a flow-through cell adapted to be fluid-connected with a blood vessel through an indwelling catheter, a reservoir for accommodating a quantity of physiologically compatible sensor correcting solution, a connecting tubing extending between the reservoir and the flow-through cell and a transfusion pump; a detector unit including a temperature sensor and a chemical sensitive sensor device both incorporated inside the flow-through cell.

Abstract: An ion activity monitoring device is disclosed, having a semi-conductor device including an ion-sensitive field-effect transistor, for detecting the activity of ions in a liquid medium of interest, and a temperature sensor, for detecting the temperature of the liquid medium of interest, a constant current circuit for supplying a drain current of a particular value to the transistor, and a processing circuit for calculating the concentration of the ions in the liquid medium of interest. The drain current is of a value satisfying the relationship of .vertline.Id/.beta..vertline..ltoreq.0.10 volt.sup.2, wherein Id represents the drain current and .beta. represents the channel characteristic value of the ion-sensitive field-effect transistor. A method for operating the transistor is also disclosed.

Abstract: An apparatus for measuring the quantities of chemical substances contained in a solution to be assayed by using a chemical-substance sensitive sensor consists of a potentiometric electrode which responds selectively to chemical substances, and a liquid-junction type reference electrode including a tube, a porous thread member housed in the front end opening of the tube and having a pore capacity of 0.2 cc/g or more and at least the surface of which is hydrophilic, a silver-silver chloride wire is provided and housed in the tube so that at one end of the wire is in contact with the thread member and the wire which extends along the tube. The wire is connected to a connector at the other end opening of the tube, an electrical insulating resin fills said tube, at least at the front end portion thereof, for fixing both the silver-silver chloride wire and the thread member by contact therewith and for stopping said tube. An internal solution is retained by suction in said porous thread member.

Abstract: A gas sensor with its photosensitivity allayed in which a hydrogen ion sensitive FET transducer having the structure of a gate-insulated field effect transistor and an Ag-AgCl reference electrode are housed inside a flexible tube in such a way that the gate part of said FET transducer and the reference electrode are located at the front end opening of the tube or an opening provided in the side wall of the tube; while the lead wires connected to the FET transducer and the reference electrode are extended along the tube, this tube is closed by filling an electrical insulation resin at least in the space of the part inside the tube wall housing the parts connecting the lead wires to the aforementioned FET transducer and to the reference electrode; further, a hydrophilic polymer containing an electrolyte is put around at least the gate part of said FET and part of the reference electrode, to envelop both of them; and whole of the surface of the aforementioned hydrophilic polymer and that of at least the part of

Abstract: The present invention provides photoelectrodes for photoelectrochemical cells, which photoelectrodes are essentially composed of a surface-chalcogenated molybdenum or tungsten metal. These photoelectrodes have long life, are highly efficient in energy conversion, and are inexpensive.

Abstract: Vinyl acetate is produced through reaction of ethylene, oxygen and acetic acid in vapor phase employing a catalyst which comprises 0.3 to 3.0 weight % of palladium metal, 0.0157 to 1.8 weight % of gold metal and 1 to 30 weight % of an alkali metal acetate, all based on the weight of the carrier or catalyst support therefor. These components are supported on said carrier or support under such conditions that (1) at least 90% by weight of each of the supported palladium and gold metals is distributed proximate the external surfaces of the carrier particles, extending to depths no greater than about 30% of the radius of each particle as measured from the external surface of each particle to the center of said particle, and (2) the proportion of gold to palladium ranges from about 5 to 60% by weight, based upon the total weight of the gold and palladium.