Abstract: Improved Newman type enzyme containing laminated membranes are disclosed for use in conjunction with polarographic cells to measure analyte concentration in solutions. The laminated membranes comprise a semipermeable outer, support layer including super large pores of greater than about 200 .ANG. in diameter. The outer layer preferably comprises pore sizes of about 380-750 .ANG. in diameter and has a percentage porosity of about 0.005-0.2%.

Abstract: Improved methods and compositions are provided to inhibit interference from formaldehyde in polarographic analytic methods. In the enzymatic oxidation of methanol to hydrogen peroxide and formaldehyde, formaldehyde serves as an interfering agent in systems where the oxygen consumed or the hydrogen peroxide produced is polarographically measured. To inhibit this interference, an amine-containing formaldehyde scavenger is added to the test system. Preferably, the scavenger comprises a polyalkyleneimine such as polyethyleneimine having a molecular weight of between about 200-1,000,000 amu. The invention is particularly well-suited for use in polarographic analytical apparatus wherein laminated membrane type enzyme electrodes are used to perform amperometric measurement with alcohol oxidase enzyme used as the oxidoreductase enzyme.

Abstract: An enzyme electrode is disclosed for use in voltammetric systems wherein a PQQ dehydrogenase enzyme is chemically bonded to a water soluble polyvinylpyridine osmium bipyridine polymer. The enzyme and polymer are adsorbed onto the surface of the electrode with the polymer providing direct electron transfer from enzyme to electrode and vice-versa without the aid of additional mediators or electron shuttles added to the system.

Abstract: An electrochemical sensor for sensing a gas dissolved in a liquid. The sensor includes a probe having a cylindrical body and a rounded face. A working electrode, a reference electrode and an auxiliary electrode are buried in the probe body and have distal ends reaching conformingly to the face. A pulsed polarizing voltage is impressed between the auxiliary electrode and the working electrode for polarizing the probe, and a capacitor is provided for storing the charge which flows to the working electrode during periods of polarization. The concentration of the dissolved gas is determined by measuring the voltage across the capacitor.

Abstract: The unique signal generating characteristics of a sensing transducer are defined by integrally incorporating an encoded form of the characteristics into the sensing transducer such that the encoded characteristics can be read by a data reader incorporated into a signal conditioner used with the sensing transducer. The encoded data is incorporated as an inseparable part of each operable sensing transducer by being molded or otherwise formed into a connecting cable of the sensing transducer or engraved or otherwise formed onto the barrel of a connector plug for interconnecting the transducer to the signal conditioner. The encoded data portion of the cable is passed through a reader externally mounted on the signal conditioner, or the encoded data on the barrel of a connector plug is read as the connector plug is inserted into a connector socket on the signal conditioner.

Abstract: An electrical connector has a first connector member including a plate-like body with retaining notches in the edges thereof, having a connector end and an attachment end, at least one strip of electrically conductive material on at least one face of the body extending from the connector end to the attachment end, and a lead wire anchored to the attachment end and attached to the strip, and a second connector member including a housing of resilient electrically insulating material forming a socket for receiving the body of the first connector member, a contact member located in the socket in position to contact the strip and having a portion for attachment to a second lead wire, and rigid retainer pins incorporated in the housing extending across the socket spaced apart to interfit with the notches, the pins being displaceable in the housing in response to insertion or withdrawal of the first connector member with respect to the second connector member.

Abstract: The relative specificity of the enzyme galactose oxidase for various substrates is controlled as a function of the electrical potential applied to the enzyme. The enzyme is incorporated into a thin layer electrochemical cell laminate having exterior membrane layers and an interior enzyme layer. An electrode located within the enzyme layer applies varying electrical potentials to the enzyme. An intermediate electron transfer agent may be used to transfer electrons to and from the enzyme and electrode.

Abstract: A transducer for measuring temperature by means of the temperature-induced resistance change of a coil of wire includes, connected to the coil, a deposited film whose resistance-versus-temperature characteristic is substantially the same as that of the wire. The complete transducer assembly is calibrated at a fixed temperature by physically removing portions of the deposited film until a desired resistance is attained. The bulk of the resistance is contributed by the wire, while the film contributes only a small percentage of the total. The transducer thus maintains the desired precision, repeatability and stability of a wirewound transducer while at the same time being capable of calibration by trimming techniques commonly used for adjusting film resistors.

Abstract: A substantially solid temperature-dependent light absorbing mass including multiple-faceted randomly oriented and distributed reflecting chips is optically coupled on the terminal end of a fiber optical light conductor.

Abstract: An apparatus for measuring the differential between a plurality of physical quantities, such as temperature, includes transducers 10 and 12 each positioned to sense the physical quantity. The transducers are preferably of the resistive or nonreactive variety. A single, controlled current power source 15 is connected sequentially to the transducers through a switching circuit 20. Each transducer is connected to the switching circuit and to an amplifier 40 through four-conductor cables 35, 45. The amplifier is therefore connected continuously to the transducers to sense both the voltage developed thereacross when the transducer is connected to the source of current through the switching circuit and also to sense continuously any other voltages, such as those that might be produced by thermocouple effects.

Abstract: A laminated membrane for use with an enzyme electrode without the need for use of a compensating electrode. The laminated membrane comprises a layer of essentially homogeneous material such as cellulose acetate or silicone rubber which will prevent passage of even low molecular weight interfering materials, an adhesive layer containing the enzyme (with or without other materials that may be blended with it), and a layer of support film which will also prevent the passage of high molecular weight interfering materials.

Abstract: A laminated membrane for use with an enzyme electrode without the need for use of a compensating electrode. The laminated membrane comprises a layer of essentially homogeneous material such as cellulose acetate or silicone rubber which will prevent passage of even low molecular weight interfering materials, an adhesive layer of the enzyme itself (with or without other materials that may be blended with it), and a layer of support film which will also prevent the passage of high molecular weight interfering materials.