Abstract: An ignition apparatus includes a plasma device, a first circuit, a second circuit, and a control unit. The plasma device produces a plasma discharge in an air-fuel mixture before an arc discharge is produced. The first circuit causes an ignition plug to start the arc discharge. The second circuit energizes a primary coil in a direction opposite to the direction of the energization by the first circuit during the arc discharge, to maintain energization of the secondary coil in the same direction as the direction of the energization started by an operation of the first circuit, to cause continuation of the arc discharge. The control unit controls operations of the first circuit, the second circuit, and the plasma device.

Abstract: A temperature measuring method and device is capable of measuring temperature of a gas, and particularly temperature of a gas that contains water vapor, in a non-contact manner and with good precision. A spectroscopic unit 10 acquires at least a light intensity in a first wavelength band and a light intensity in a second wavelength band, from radiated light from water vapor that is an object to be measured. The first wavelength band and the second wavelength band are both near infrared region bands. A central wavelength of the first wavelength band and a central wavelength of the second wavelength band are set to be mutually different values. A temperature calculation unit calculates temperature of water vapor using a ratio of light intensity in the first wavelength band to light intensity in the second wavelength band.

Abstract: An ignition apparatus includes a plasma device, a first circuit, a second circuit, and a control unit. The plasma device produces a plasma discharge in an air-fuel mixture before an arc discharge is produced. The first circuit causes an ignition plug to start the arc discharge. The second circuit energizes a primary coil in a direction opposite to the direction of the energization by the first circuit during the arc discharge, to maintain energization of the secondary coil in the same direction as the direction of the energization started by an operation of the first circuit, to cause continuation of the arc discharge. The control unit controls operations of the first circuit, the second circuit, and the plasma device.

Abstract: A temperature measuring method and device is capable of measuring temperature of a gas, and particularly temperature of a gas that contains water vapor, in a non-contact manner and with good precision. A spectroscopic unit 10 acquires at least a light intensity in a first wavelength band and a light intensity in a second wavelength band, from radiated light from water vapor that is an object to be measured. The first wavelength band and the second wavelength band are both near infrared region bands. A central wavelength of the first wavelength band and a central wavelength of the second wavelength band are set to be mutually different values. A temperature calculation unit calculates temperature of water vapor using a ratio of light intensity in the first wavelength band to light intensity in the second wavelength band.