Carbon controlling with O2-probe and L-probe

Gas carburizing still plays an important role in heat treatment. Temperature and carbon potential (C-Potential) of the atmosphere are the essential parameters for the process control. Till this day there is no direct measurement method for C-Potential which could be used for online process control. The measurement of the oxygen partial pressure in the furnace atmosphere is the most used indirect method for the control of the C-Potential. There are different types of oxygen probes. In this article the essential differences in construction will be discussed as well as their advantages and disadvantages.