Abstract: A biological gas detection apparatus of an embodiment of the present invention includes: a sensor unit including plural types of gas sensors; a control unit of the sensor unit; a data recording unit; and a data analyzing unit, wherein the data recording unit includes a database on properties of sensitivities of the gas sensors for a single body of a desired gas component, a single body of an interference gas component, and a mixed gas of these that are included in the biological gas, and the data analyzing unit calculates concentration of the desired gas component based on sensitivities of the gas sensors output when detecting the biological gas and the database.

Abstract: A biological gas detection apparatus of an embodiment of the present invention includes: a sensor unit including plural types of gas sensors; a control unit of the sensor unit; a data recording unit; and a data analyzing unit, wherein the data recording unit includes a database on properties of sensitivities of the gas sensors for a single body of a desired gas component, a single body of an interference gas component, and a mixed gas of these that are included in the biological gas, and the data analyzing unit calculates concentration of the desired gas component based on sensitivities of the gas sensors output when detecting the biological gas and the database.

Abstract: A water quality analyzer comprises: sensor electrodes 1a, 1b made of different metals from each other, the electrodes in a liquid of inspecting object generating a sense voltage in proportion to the liquid's impurities concentration; an operational amplifier OP1 amplifying the sense voltage without inverting to provide for a CPU 3; a resistor R0 whose one end is connected to the electrode 1a; and a voltage divider 2 applying a voltage obtained by dividing the sense voltage by a prescribed division ratio to R0's another end. The CPU 3 calculates input signal from OP1 to obtain chlorine concentration and displays the calculated result on a LCD 4 in a measurement mode, and sets the division ratio of the divider 2 so that sense voltage across electrodes 1a, 1b soaked in a liquid including prescribed concentration chloride approximately agrees with a reference voltage of prescribed concentration in a sense-voltage calibration mode.

Abstract: A gas detection apparatus A comprises a signal processing circuit 20, a Wheatstone bridge circuit 21, integrating circuits 22 and 23, a differential amplification circuit 24, a direct current power supply circuit 25, a heater voltage application circuit 26. The Wheatstone bridge circuit 21 is configured of parallel combination of series circuits: one composed of a catalytic combustion type gas sensor 1 and a load resistor R1, and the other composed of a resistor R2, a variable resistor VR1 and a resistor R3. The heater voltage application circuit 26 is configured to generate a pulsed heater voltage by switching a direct current voltage of the direct current power supply circuit 25 through a transistor TR1 for applying the pulsed heater voltage to the Wheatstone bridge circuit 21. The integrating circuit 22 integrates a voltage at a connection point between the gas sensor 1 and the load resistor R1.

Abstract: A water quality analyzer comprises: sensor electrodes 1a, 1b made of different metals from each other, the electrodes in a liquid of inspecting object generating a sense voltage in proportion to the liquid's impurities concentration; an operational amplifier OP1 amplifying the sense voltage without inverting to provide for a CPU 3; a resistor R0 whose one end is connected to the electrode 1a; and a voltage divider 2 applying a voltage obtained by dividing the sense voltage by a prescribed division ratio to R0's another end. The CPU 3 calculates input signal from OP1 to obtain chlorine concentration and displays the calculated result on a LCD 4 in a measurement mode, and sets the division ratio of the divider 2 so that sense voltage across electrodes 1a, 1b soaked in a liquid including prescribed concentration chloride approximately agrees with a reference voltage of prescribed concentration in a sense-voltage calibration mode.

Abstract: A water quality analyzer comprises: sensor electrodes 1a, 1b made of different metals from each other, the electrodes in a liquid of inspecting object generating a sense voltage in proportion to the liquid's impurities concentration; an operational amplifier OP1 amplifying the sense voltage without inverting to provide for a CPU 3; a resistor R0 whose one end is connected to the electrode 1a; and a voltage divider 2 applying a voltage obtained by dividing the sense voltage by a prescribed division ratio to R0's another end. The CPU 3 calculates input signal from OP1 to obtain chlorine concentration and displays the calculated result on a LCD 4 in a measurement mode, and sets the division ratio of the divider 2 so that sense voltage across electrodes 1a, 1b soaked in a liquid including prescribed concentration chloride approximately agrees with a reference voltage of prescribed concentration in a sense-voltage calibration mode.

Abstract: The hydrogen gas sensor is a catalytic combustion hydrogen gas sensor with a detection element 1, and is characterized by comprising a measuring circuit configured to selectively provide a normal voltage mode for applying a normal voltage to the detection element 1 and a high voltage mode for applying a high voltage higher than said normal voltage to said detection element 1. Thereby, upon energization of the hydrogen gas sensor, the detection element 1 can be first applied the high voltage to be rapidly heated to raise a temperature of the detection element 1 immediately. And then, the detection element 1 can be applied the normal voltage to be heated to be kept at a predetermined temperature at which the hydrogen gas is detected.

Abstract: A gas detection apparatus A comprises a signal processing circuit 20, a Wheatstone bridge circuit 21, integrating circuits 22 and 23, a differential amplification circuit 24, a direct current power supply circuit 25, a heater voltage application circuit 26. The Wheatstone bridge circuit 21 is configured of parallel combination of series circuits: one composed of a catalytic combustion type gas sensor 1 and a load resistor R1, and the other composed of a resistor R2, a variable resistor VR1 and a resistor R3. The heater voltage application circuit 26 is configured to generate a pulsed heater voltage by switching a direct current voltage of the direct current power supply circuit 25 through a transistor TR1 for applying the pulsed heater voltage to the Wheatstone bridge circuit 21. The integrating circuit 22 integrates a voltage at a connection point between the gas sensor 1 and the load resistor R1.

Abstract: The hydrogen gas sensor is a catalytic combustion hydrogen gas sensor with a detection element 1, and is characterized by comprising a measuring circuit configured to selectively provide a normal voltage mode for applying a normal voltage to the detection element 1 and a high voltage mode for applying a high voltage higher than said normal voltage to said detection element 1. Thereby, upon energization of the hydrogen gas sensor, the detection element 1 can be first applied the high voltage to be rapidly heated to raise a temperature of the detection element 1 immediately. And then, the detection element 1 can be applied the normal voltage to be heated to be kept at a predetermined temperature at which the hydrogen gas is detected.

Abstract: A water quality analyzer comprises: sensor electrodes 1a, 1b made of different metals from each other, the electrodes in a liquid of inspecting object generating a sense voltage in proportion to the liquid's impurities concentration; an operational amplifier OP1 amplifying the sense voltage without inverting to provide for a CPU 3; a resistor R0 whose one end is connected to the electrode 1a; and a voltage divider 2 applying a voltage obtained by dividing the sense voltage by a prescribed division ratio to R0's another end. The CPU 3 calculates input signal from OP1 to obtain chlorine concentration and displays the calculated result on a LCD 4 in a measurement mode, and sets the division ratio of the divider 2 so that sense voltage across electrodes 1a, 1b soaked in a liquid including prescribed concentration chloride approximately agrees with a reference voltage of prescribed concentration in a sense-voltage calibration mode.

Abstract: A gas chromatograph having the capability of performing a reliable measurement under a condition that the baseline of a detector output is stabilized, and a breath component analyzer using the same are provided. This gas chromatograph comprises a gas separation column accommodating a member for causing a flow delay depending on gas component; air pump for supplying an air as a carrier gas into the gas separation column; gas supply port formed in a gas flow channel extending between the air pump and the gas separation column, and adapted to supply a subject gas containing a target gas component to be detected into the carrier gas flowing in the gas flow channel; buffer tank provided upstream of the gas supply port; and a detector for detecting the gas component of the subject gas supplied into the gas separation column.