- Test conditions
- Data processing and decision
Put the wafer with 5mmX5mm grid on the specimen to check the rust. When the rust appear in the grid, it should be regard as one rust unit(n), if the rust cross the two grid, regard as two rust unit, but if several rust located in one grid, it should be regard as one rust unit. The frequency of the rust spot, we have one formula to calculate: frequency rate=n/NX100% Annotations: N- number of the grid; n- number of the grid with rust spot. Decision the level for the calculated frequency of the corrosion spot according to the below table, the lower test samp lelever is the item lever.