Method of controlling heater systems

A method comprising:

• controlling, during an initialization phase, a variable voltage applied to a Joule-heated emitting electrical conductor and modulated according to a duty cycle, the duty cycle being variable between:
• a high-average power duty cycle during hot periods so that the Joule-heated emitting electrical conductor is subjected to a high-average power in order to reach and maintain an emission temperature so that the Joule-heated emitting electrical conductor emits a radiation at a specific wavelength;
• and
• a low-average power duty cycle during cold periods alternated to the hot periods, so that the Joule-heated emitting electrical conductor is subjected to a low-average power in order to reach a temperature smaller than the emission temperature so that the Joule-heated emitting electrical conductor does not emit the radiation at the specific wavelength,
• wherein the low-average power duty cycle is smaller than the high-average power duty cycle, and
• wherein, during the initialization phase, a decrement between the high-average power and the low-average power is maintained constant and an ambient temperature is also maintained constant;
• and
• defining, during an operation phase, the low-average power duty cycle such that a decrement between the high-average power and the low-average power is the same as the decrement between the high-average power and the low-average power during the initialization phase,
• wherein the specific wavelength is a characteristic wavelength of a particular fluid.

A method comprising:

• emitting, by a Joule-heated emitting electrical conductor, a radiation at a specific wavelength at an emission temperature, wherein emitting is subjected to a duty cycle, the duty cycle being variable between:
• a high-average power duty cycle during hot periods so that the Joule-heated emitting electrical conductor is subjected to a high-average power in order to reach the emission temperature so that the Joule-heated emitting electrical conductor emits the radiation at the specific wavelength;
• and
• a low-average power duty cycle during cold periods alternated to the hot periods so that the Joule-heated emitting electrical conductor is subjected to a low-average power to reach a temperature smaller than the emission temperature so that the Joule-heated emitting electrical conductor does not emit the radiation at the specific wavelength,
• wherein the high-average power duty cycle and the low-average power duty cycle are defined based on at least one temperature-indicative measured value indicative of a measured ambient temperature, and
• wherein the radiation at the specific wavelength is a characteristic wavelength of a fluid.