Abstract: In a leakage detection system configured by arranging a number of gas sensors, a leakage spot is promptly and accurately estimated. An output voltage of the each sensor is converted into concentration, and a time differential coefficient of the concentration is obtained. A leakage spot is estimated to be on a straight line connecting between the sensors for which the time differential coefficient is large.

Abstract: In a hydrogen gas station where a great number of sensors are installed, in case hydrogen leakage occurs, sensors in the vicinity of the leakage location start to transmit a warning to an access point all at once. This causes channel capacity saturation and failure to transmit a warning to the access point. Nodes and the access point are connected to each other by an uplink channel and a downlink channel. The access point detects congested/uncongested status of the uplink channel by using a wireless transmitter module and notifies the nodes of the congested/uncongested status of the channel by means for transmitting onto the downlink channel. Meanwhile, each node controls its transmission operation, according to the hydrogen concentration level detected by its hydrogen sensor and the uplink channel congested/uncongested status notified from the access point. In this way, channel overflow due to access congestion in case of hydrogen leakage can be prevented.

Abstract: It is an object of the present invention to minimize the power for heating of an FET-type gas sensor using an FET to ensure a long operating life. Two terminals 10 and 11 are arranged at a sensitive electrode 31 formed on a gate insulation film of an FET, and different potentials are applied thereto to cause a current to flow. The sensitive electrode 31 functions as a heating element by causing a current to flow in the sensitive electrode 31 which needs to be heated, allowing the FET-type gas sensor to be heated most efficiently. Furthermore, the terminals 10 and 11 configure a part of a temperature detector which measures the temperature of the heated sensitive electrode 31.

Abstract: A gas detection system capable of suppressing the power consumption of the system using gas sensors required for heating for measurement at high accuracy, comprising a server and a plurality of gas sensors connected by way of wireless communication with the server, in which each of the gas sensors is provided with a heater, a controller for controlling the ON-OFF for the power supply to the heater and a comparator for comparing the detected gas concentration with a predetermined threshold value. In the gas detection system, electric power is not usually supplied to the heater in each of the gas sensors and the gas sensor measures the gas concentration at a low accuracy and always compares it with the threshold value. In a case where the gas concentration exceeds the threshold value in one of the gas sensors, it turns the heater of its own to ON thereby switching the measurement to that at high accuracy and turns the heater to OFF upon completing the measurement.

Abstract: The present invention provides a manufacturing method enabling suppression of threshold voltage fluctuation without giving any damage to a gate insulating film when a transistor structure is formed at first in a field effect transistor type of gas sensor and then an electrode with a material responsive to a gas to be detected is formed. The gate insulating film is a film stack including at least an SiO2 film and an SRN (Si-rich nitride) film. The SRN film functions as a etching stopper film when the gate insulating film is exposed by etching of an inter-layer insulating film. Pressure resistance of the gate insulating film is preserved with SiO2. An electric charge in the SRN film can be removed with a lower voltage as compare to that required for removing an electric charge in the Si3N4 film, which enables suppression of threshold voltage fluctuation in gas sensor transistors.

Abstract: In a hydrogen gas station where a great number of sensors are installed, in case hydrogen leakage occurs, sensors in the vicinity of the leakage location start to transmit warning to an access point all at once. This causes channel capacity saturation and failure to transmit warning to the access point. Nodes and the access point are connected each other by an uplink channel and a downlink channel. The access point detects congested/uncongested status of the uplink channel by using a wireless transmitter module and notifies the nodes of the congested/uncongested status of the channel by means for transmitting onto the downlink channel. Meanwhile, each node controls its transmission operation, according to the hydrogen concentration level detected by its hydrogen sensor and the uplink channel congested/uncongested status notified from the access point. In this way, channel overflow due to access congestion in case of hydrogen leakage can be prevented.

Abstract: A gas detection system capable of suppressing the power consumption of the system using gas sensors required for heating for measurement at high accuracy, comprising a server and a plurality of gas sensors connected by way of wireless communication with the server, in which each of the gas sensors is provided with a heater, a controller for controlling the ON-OFF for the power supply to the heater and a comparator for comparing the detected gas concentration with a predetermined threshold value. In the gas detection system, electric power is not usually supplied to the heater in each of the gas sensors and the gas sensor measures the gas concentration at a low accuracy and always compares it with the threshold value. In a case where the gas concentration exceeds the threshold value in one of the gas sensors, it turns the heater of its own to ON thereby switching the measurement to that at high accuracy and turns the heater to OFF upon completing the measurement.

Abstract: A magnetic field measurement system for canceling an external field is provided, in which plurality of sensing magnetometers (3) for measuring a magnetic field signal in a direction perpendicular to the center axis of a cylindrical magnetic shield (1) are arranged in two dimensions on a plane parallel to the center axis and a reference magnetometer (4) for measuring the external field parallel to the center axis as a reference signal is disposed on a plane perpendicular to the plane parallel to the center axis. The reference signal multiplied by a specified factor is subtracted from a difference between signals from the adjacent sensing magnetometers (3). The magnetic field measurement system allows measurement of an extremely weak magnetic field by efficiently canceling the external field.

Abstract: A magnetic field measurement system for canceling an external field is provided, in which plurality of sensing magnetometers (3) for measuring a magnetic field signal in a direction perpendicular to the center axis of a cylindrical magnetic shield (1) are arranged in two dimensions on a plane parallel to the center axis and a reference magnetometer (4) for measuring the external field parallel to the center axis as a reference signal is disposed on a plane perpendicular to the plane parallel to the center axis. The reference signal multiplied by a specified factor is subtracted from a difference between signals from the adjacent sensing magnetometers (3). The magnetic field measurement system allows measurement of an extremely weak magnetic field by efficiently canceling the external field.

Abstract: An apparatus can detect a magnetic field with a high sensitivity using an ordinary-temperature pickup coil even when the pickup coil is arranged outside a cryostat. Specifically, the apparatus for measuring a magnetic field includes a pickup coil for detecting an external magnetic field, a SQUID electrically or magnetically connected to the pickup coil, a cryostat for holding the SQUID at low temperatures, and a driving device for driving the SQUID. The pickup coil is made of a normal-conducting material and is placed at an ordinary temperature outside the cryostat. By arranging outside the cryostat, the pickup coil can be brought close to a subject and can thereby detect a weak magnetic field in the subject with a high sensitivity.

Abstract: A biomagnetic field measuring apparatus includes a plurality of SQUID magneto-meters for measuring a biomagnetic field generated from a living body, living-body signal measuring devices and for measuring and collecting living-body signals generated periodically, an operation processing device for operation processing the biomagnetic field signal and the living-body signal measured simultaneously as pairs in a plurality of directions, and a display unit for displaying a result of the operation processing. Change in time of excitation can be grasped in detail by using a small number of maps without presumption of a magnetic field source and display of many iso-magnetic field maps.

Abstract: An apparatus for measuring bio-magnetic fields includes a plurality of magnetometers for detecting magnetic fields generated from a live body; a driving circuit for driving the magnetometers; a computer for collecting output signals of the driving circuit in the form of data representing at least one waveform of the magnetic fields generated from the live body and for performing an arithmetic processing on the data representing the waveform of magnetic fields, a display unit, and at least one signal processing circuit for processing output signals of the driving circuit. The computer further performs an arithmetic processing of first-order differentiation on the waveform of the magnetic fields in a z direction with respect to time in order to create an arrow map and a contour map. The apparatus can also detect mechanical movement which occurs as blood flows in organs and organs move.

Abstract: A gradiometer integrating pickup coils comprises pickup coils 11Xp, 11Xn magnetically connected to a SQUID through associated input coils 2, and pickup coils 11Yp, 11Yn magnetically connected to a SQUID through associated input coils 2, respectively. Two superconducting loops are connected in series to each of the SQUIDs, when viewed from Josephson junctions 5. The input coils 2 form superconducting closed loops together with the pickup coils 11Xp, 11Xn, 11Yp, 11Yn associated therewith. The SQUIDs are respectively connected to form an 8-figured shape as a whole such that currents flow in two superconducting loops of each SQUID in opposite directions to each other, with respect to the application of a uniform field, in order to reduce environmental magnetic field noise.

Abstract: The invention provides the configuration which gives an open feeling of a small-sized magnetic shield and precision measurement equipment which uses the magnetic shield and the S/N ratio of which is high. A magnetic shield in which openings at both ends of the cylindrical magnetic shield made of ferromagnetic material and having a surface parallel to the axial direction of the superconducting ring are arranged between superconducting rings which form a pair of closed loops and build ringed superconducting wire inside opposite to a plane of the superconducting ring is used for biomagnetic measurement equipment. A direction of a plane of a detection coil of the biomagnetic measurement equipment is arranged in parallel with the axis of the superconducting ring. As a result, the magnetic shield which gives an open feeling, which is light and small-sized can be realized.

Abstract: A magnetic field measuring apparatus has a magnetic field shielding apparatus including non-magnetic cylindrical members on which high-permeability sheets are located in a state of being partially overlapped with each other. The cylindrical members are located to surround an axis of a first direction concentrically and having a hollow portion, the cylindrical member located on an innermost-side having a first opening at one end of the first direction, a second opening at the other end of the first direction, and a third opening penetrating the cylindrical members in a direction perpendicular to the axis of the first direction. In addition, the magnetic field measuring apparatus has a living-body holder located in an inner-side space of the cylindrical member and a cryostat inserted into the third opening and maintaining SQUID magnetic-flux meters.

Abstract: An apparatus can detect a magnetic field with a high sensitivity using an ordinary-temperature pickup coil even when the pickup coil is arranged outside a cryostat. Specifically, the apparatus for measuring a magnetic field includes a pickup coil for detecting an external magnetic field, a SQUID electrically or magnetically connected to the pickup coil, a cryostat for holding the SQUID at low temperatures, and a driving device for driving the SQUID. The pickup coil is made of a normal-conducting material and is placed at an ordinary temperature outside the cryostat. By arranging outside the cryostat, the pickup coil can be brought close to a subject and can thereby detect a weak magnetic field in the subject with a high sensitivity.

Abstract: A gradiometer integrating pickup coils comprises pickup coils 11Xp, 11Xn magnetically connected to a SQUID through associated input coils 2, and pickup coils 11Yp, 11Yn magnetically connected to a SQUID through associated input coils 2, respectively. Two superconducting loops are connected in series to each of the SQUIDs, when viewed from Josephson junctions 5. The input coils 2 form superconducting closed loops together with the pickup coils 11Xp, 11Xn, 11Yp, 11Yn associated therewith. The SQUIDs are respectively connected to form an 8-figured shape as a whole such that currents flow in two superconducting loops of each SQUID in opposite directions to each other, with respect to the application of a uniform field, in order to reduce environmental magnetic field noise.

Abstract: A biomagnetic field measuring apparatus includes a plurality of SQUID magneto-meters for measuring a biomagnetic field generated from a living body, living-body signal measuring devices and for measuring and collecting living-body signals generated periodically, an operation processing device for operation processing the biomagnetic field signal and the living-body signal measured simultaneously as pairs in a plurality of directions, and a display unit for displaying a result of the operation processing. Change in time of excitation can be grasped in detail by using a small number of maps without presumption of a magnetic field source and display of many iso-magnetic field maps.

Abstract: An apparatus for measuring bio-magnetic fields includes a plurality of magnetometers for detecting magnetic fields generated from a live body; a driving circuit for driving the magnetometers; a computer for collecting output signals of the driving circuit in the form of data representing at least one waveform of the magnetic fields generated from the live body and for performing an arithmetic processing on the data representing the waveform of magnetic fields; a display unit; at least one signal processing circuit for processing output signals of the driving circuit; a signal generator for generating high-frequency AC current to be applied to the live animal body; and an electric wire for transmitting the high-frequency AC current from the signal generator to the live body via a plurality of electrodes to be attached to a plurality of points on the live body.

Abstract: A magnetic field measuring apparatus has a magnetic field shielding apparatus including non-magnetic cylindrical members on which high-permeability sheets are located in a state of being partially overlapped with each other. The cylindrical members are located to surround an axis of a first direction concentrically and having a hollow portion, the cylindrical member located on an innermost-side having a first opening at one end of the first direction, a second opening at the other end of the first direction, and a third opening penetrating the cylindrical members in a direction perpendicular to the axis of the first direction. In addition, the magnetic field measuring apparatus has a living-body holder located in an inner-side space of the cylindrical member and a cryostat inserted into the third opening and maintaining SQUID magnetic-flux meters.