Customers have observed that the copper wire in the thermocouples turns black. What causes this and is it harmful to the thermocouple?
This is a normal occurrence when copper is exposed to high temperatures in the presence of oxygen and/or water vapor/steam. This can occur in both autoclaves and ovens. The oxidation is much faster in ovens. There is still some debate as to the harm caused by light oxidation. But when the oxidation turns black and then to dull porous or fractured black with the generation of particulates, the agreement is more universal that the uniformity along the wire and the conformity will be detrimentally affected. At this point, it is best to replace the thermocouples rather than risk inaccurate data.
September 9, 2009 at 10:25 am | Uncategorized | No comment