Abstract: A grounded burner, actuators adjusting the supply of fuel and air to the burner, an ionization electrode in the flame region, a flame amplifier at the ionization electrode generating an ionization signal, and a final control device are included in a burner system. During air ratio control mode, the final control device sets a first actuator and adjusts a second actuator. During voltage control mode a voltage regulator controls the AC voltage source using the AC voltage measured by the voltmeter, in conjunction with an ionization current amplifier. The voltmeter is connected in parallel with a sequence of the ionization electrode, the flame region, the burner and the input of the ionization current amplifier. The voltage regulator is connected to the voltmeter such that, during voltage control mode, the time-averaged current caused by the voltmeter through the connection is less than 5% of the time-averaged current through the ionization electrode.

Abstract: A grounded burner, actuators adjusting the supply of fuel and air to the burner, an ionization electrode in the flame region, a flame amplifier at the ionization electrode generating an ionization signal, and a final control device are included in a burner system. During air ratio control mode, the final control device sets a first actuator and adjusts a second actuator. During voltage control mode a voltage regulator controls the AC voltage source using the AC voltage measured by the voltmeter, in conjunction with an ionization current amplifier. The voltmeter is connected in parallel with a sequence of the ionization electrode, the flame region, the burner and the input of the ionization current amplifier. The voltage regulator is connected to the voltmeter such that, during voltage control mode, the time-averaged current caused by the voltmeter through the connection is less than 5% of the time-averaged current through the ionization electrode.

Abstract: A method for monitoring a combustion process in the infrared wavelength range includes using a laser, which transmits a laser light beam along a measurement path in a certain wavelength range, which is selected in such a way that a gas therein to be detected in the combustion process has an absorption line, and that the emission wavelength of the laser detects the absorption line of the gas to be detected upon the tuning in the selected wavelength range. The concentration of the gas is determined as a function of the absorbed energy of the laser light beam. The intensity of the laser light beam is detected and is analyzed in order to determine the existence of a flame in the combustion process, and/or the quality of the flame.