When the cell is at operating temperature and there are unequal oxygen
concentrations across the cell, oxygen ions will travel from the high oxygen
partial pressure side to the low oxygen partial pressure side of the cell. The
resulting logarithmic output voltage is approximately 50 mV per decade. The
output is proportional to the inverse logarithm of the oxygen concentration.
Therefore, the output signal increases as the oxygen concentration of the
sample gas decreases. This characteristic enables the Oxymitter 4000 to
provide exceptional sensitivity at low oxygen concentrations