The main screen of our surface oxide tester provides a SPC or Test History Window. We have heard that this is extremely useful for managers can rapidly view the results of many recent tests as they pass by.
Of course, the main purpose of SPC is for trend recognition... To be able to see when a process is drifting out of control before it becomes critical.
Finally with the understanding that the amount of subsurface oxides from sample to sample are often highly variable in nature, Test History can be very useful in observing this volatility characteristic of subsurface oxides. This observation can be discerned even clearer when comparing the Test History of cuprous (Cu2O) and cupric (CuO) oxides, it will tend to be the cupric oxides that are high and volatile when subsurface oxides are present. Using the DCD Method when necessary, the cuprous oxides will be more steady.