METHOD AND DEVICE FOR RECALIBRATING A MEASURING SYSTEM FOR REGULATING A FUEL-AIR MIXTURE IN A HEATING DEVICE

The invention relates to a method for re-calibrating the calibration data of a first measurement system (S1) for measuring a first ionization signal in a flame region (2) of a heater (1) operated withcombustion air and gas, wherein the first measurement system (S1) measures the first ionization signal (I1), the first ionization signal is derived on the basis of a first ionic current flowing through the flame region (2) from the ionization electrode (8) to the counter electrode (9), and a ratio (lambda) of combustion air to fuel gas during combustion in the heater (1) is determined and adjusted from the first ionic current by means of adjustment data. The first measuring system (S1) is re-calibrated at least in accordance with a pre-determinable criterion or at a pre-determinable time interval, and the re-calibration is carried out by means of an ignition electrode (7) for ignition in the heater (1), wherein the ignition electrode (7) is operated to generate a second ionization signal(I2). The invention also relates to a device, in particular for carrying out the aforementioned method.