To form a layer separating two volumes of aqueous solution, there is used an apparatus comprising elements defining a chamber, the elements including a body of non-conductive material having formed therein at least one recess opening into the chamber, the recess containing an electrode. A pre-treatment coating of a hydrophobic fluid is applied to the body across the recess. Aqueous solution, having amphiphilic molecules added thereto, is flowed across the body to cover the recess so that aqueous solution is introduced into the recess from the chamber and a layer of the amphiphilic molecules forms across the recess separating a volume of aqueous solution introduced into the recess from the remaining volume of aqueous solution.

Formation of layers of amphiphilic molecules

A sensor system (1) for measuring an electrical signal across a lipid bilayer is formed by a cell (2) and an electrical reader unit (3) which are connectable together. The cell (2) is capable of supporting a lipid bilayer across an aperture (11) in a membrane (10) and has a construction which is cheap to manufacture. The reader unit (3) is a portable device which monitors an electrical signal generated in the connected cell (2) to allow analysis of that electrical signal. The sensor system (1) is intended for use outside of a laboratory setting.

Lipid bilayer sensor system

A method for determining at least one characteristic of a multiphase fluid including the steps of applying alternating energy of a predetermined amplitude to a portion of a multiphase fluid and measuring the electrical impedance spectrum across the portion of multiphase fluid whereby a characteristic of the multiphase fluid can be determined from the measured electrical impedance spectra.

Method and apparatus for characterising multiphase fluid mixtures

An array of membranes comprising amphipathic moleculesis formed using an apparatus comprising a support defining an array of compartments. Volumes comprising polar medium are provided within respective compartments and a layer comprising apolar medium is provided extending across the openings with the volumes. Polar medium is flowed across the support to displace apolar medium and form a layer in contact with the volumes, forming membranes comprising amphipathic molecules at the interfaces. In one construction of the apparatus, the support that comprises partitions which comprise inner portions and outer portions. The inner portions define inner recesses without gaps therebetween that are capable of constraining the volumes comprising polar medium contained in neighbouring inner recesses from contacting each other. The outer portions extend outwardly from the inner portions and have gaps allowing the flow of an apolar medium across the substrate.

Formation of array of membranes and apparatus therefor

A volume flow controller (1) for controlling the flow of a gas mixture of variable proportions through a conduit (3) has a valve means (5) for regulating the flow of gas through the conduit, a drive means (9) for driving the valve means, a volumetric flow meter (7), such as a Pelton wheel, for measuring the flow of gas through the conduit, which provides a feedback signal (29) for comparison with a setpoint signal (17) in an amplifier (15) which generates an adjustment signal (11) which is fed to the drive means. The setpoint signal is generated by a setpoint signal generating means (19), which comprises a potentiometer (21) for inputting a value corresponding to a desired flow rate and a slowdown circuit (23) consisting of a resistor (25) and a capacitor (27) for delaying the change in the setpoint from the previous setpoint to the desired setpoint for a period of time sufficient to compensate for the delay in response inherent in the volumetric flow meter, thus providing smooth and stable control of the gas flow. Preferably, the potentiometer is a digital potentiometer (403), which voltage is variable by independent manipulation of rotary encoders (417).

Volume flow controller

PURPOSE: To compensate a measuring error due to a humidity difference and a temperature difference by subtracting an influence portion due to the humidify difference and the temperature difference of a standard gas and a gas to be measured and the offset component of an odorant sensor from the output of the odorant sensor. CONSTITUTION: The characteristic of an odorant sensor 5 is decided in such a way that a function f 1 which depends only on the concentration (c) of an odorant substance and a function which corresponds to a change and a change with the elapsed time due to temperature and humidity are added. A changeover means 2 changes over the connection to supply the output of a standard-gas generation means 1 to a measuring cell 4, the temperature and the humidity of a standard gas are measured by sensors 6, 7, and an arithmetic circuit 10 operates and outputs an influence portion due to a temperature difference and a humidity difference so as to be 0. A subtraction circuit 11 to which values are input from the sensor 5 and the circuit 10 subtracts them, and an output 102a becomes 0. Then, the means 2 changes over the connection to feed gas to be measured 4 from an inlet 100, the circuit 10 operates an influence portion due to the temperature difference and the humidity difference of the standard gas and a gas to be measured, it is subtracted by the circuit 11 in the same manner, and the output 102a≈f 1 (c) is output. Consequently, the output depends only on the concentration of the odorant substance. COPYRIGHT: (C)1995,JPO

Gas measuring apparatus

PURPOSE:To measure a frequency change even with a counter having a small number of bits by subtracting new measured value from preceding new measured value by (n) and dividing the cumulative difference by (n). CONSTITUTION:A sensor 1 which sucks smells, etc., and the resonance frequency of which changes is set in a gas to be measured and resonates when an oscillation circuit 2 is driven. A counter 11 inputs the resonance frequency signal of the sensor 1 and measures the frequency of the signal. A storage circuit 13 and subtracting circuit 14 input the measured value of the counter 11. The circuit 13 stores past (n) measured values and, when a new measured value is inputted, outputs the oldest value among the storing measured values, namely, the measured value preceding the new measured value by (n) measured values to the circuit 14. The circuit 14 subtracts the oldest measured value from the new measured value and outputs the difference to an adding circuit 15 and the circuit 15 adds the output signal of the circuit 14 to a cumulative value stored in a storage circuit 16 and stores the new cumulative value in the circuit 16. Then a dividing circuit 8 divides the output signal of the circuit 16 by (n) and a frequency converting circuit 9 converts the output of the circuit 8 into a frequency value from the count value and outputs a signal 100a.

Frequency change measuring instrument

PURPOSE: To provide a densitometer for measuring the density of each phase of a multiphase fluid accurately through simple structure by determining the volume ratio among respective phases based on the dielectric constant depending on the frequency. CONSTITUTION: A multiphase fluid mixed with water oil or gas flows through a duct 10 in the direction shown by an arrow Y and passes between the electrodes 21a, 21b of a multiphase densitometer 20. In the multiphase densitometer 20, a high frequency sine wave having variable frequency is applied from an impedance measuring circuit 22 between the electrodes 21a, 21b secured to the duct 10 and the capacitive impedance between the electrodes is measured. Since a predetermined relationship is satisfied between the dielectric constant of a dielectric and the capacitance between the electrodes, the density of the fluid can be determined for each phase by measuring the variation in the capacitance, i.e., impedance, for each phase of water, oil or gas when the frequency is varied and then determining the volume ratio among respective phases through an arithmetic circuit 23. COPYRIGHT: (C)1996,JPO

Densitometer for multiphase fluid

PURPOSE: To provide a sensor having high reliability by a method wherein a microrecessed part which has an electrode at the bottom is formed on a base surface, a lipid film 15 is adhered on the same time surface making a water phase between this film and the recessed part. CONSTITUTION: A recessed part 12 is formed on the surface of an insulating base 11 and a space between a lipid film 15 and the recessed part is filled with water or some kind of a water solution to form a water phase 16. A metallic electrode 13 is formed at the bottom of the recessed part 12, wiring is made on an external terminal 14, and a chemical material sensor 1 is formed. A water tank 2 is filled with liquid 3 to be measured, and a reference electrode 4 and the sensor 1 are immersed. When a chemical material molecule in the liquid 3 is absorbed to the film 15, load density of a film surface and film structure are changed, a film potential is generated on the both sides of the film 15 to produce a potential difference between the electrodes 13 and 4. By measuring the potential difference by means of a potential measuring device 5, a kind and concentration of a chemical material in the liquid 3 and a potential responding to a kind of a lipid film 15 can be fetched. COPYRIGHT: (C)1992,JPO&Japio

Lipid film type chemical material sensor

PURPOSE: To provide a multiphase flow meter, by which the constitution can be comparatively simplified, and a flow by each phase can be measured with high accuracy. CONSTITUTION: Impedance measuring circuits 22, 32 measure a change of electrostatic capacity between electrodes varied according to a dielectric constant of a mixed-phase fluid of multiphase by applying the voltage, the frequency of which is varied between the electrodes. Arithmetic circuits 23, 33 receive the output of the impedance measuring circuits 22, 32 to obtain the ratio of each phase of a mixed-phase fluid by operation. Further, there are provided two sets of mixed-phase density meters 20, 30 constructed so that both electrodes are installed at a designated space in a pipeline 10 where a mixed-phase fluid to be measured flows, and a correlative arithmetic circuit 40, to which ratio signals obtained from two sets of mixed-phase density meters 20, 30 are added, and which is adapted to obtain a flow by each phase of a mixed-phase fluid by detecting fluctuation caused by the flow of a mixed-phase fluid to obtain the delay time corresponding to the peak of the correlation function of the respective signals. COPYRIGHT: (C)1996,JPO

Kenta Mikuriya

Papers

Gas measuring apparatus

Frequency change measuring instrument

Densitometer for multiphase fluid

Lipid film type chemical material sensor

Multiphase flow meter