A piston for an internal combustion engine is provided. The carboxylic acids andor alkali metal salts and the alkylolamines are present in the fluid in respective amounts such that, at 25\xb0 C. Responsive to a measurement of at least one communication parameter of a commutated bitstream which is transmitted to the client, the data source can change a commutation format of the commutated bitstream. At the time of initial start-up, moisture generated in the low-grade humidified type fuel cell unit is supplied to the electrolyte of the humidified type fuel cell unit. A further equalisation of the phase compensation occurs by means of a correction device in a measuring chip, which is connected in series with the inputs for voltage determination and current determination.