· These gauges are made for simple pass/fail inspection
· Basically there are two separate, or combined gauges for each feature to be measured.
· One gauge must fit inside the feature, and the second must not. In other words the GO gauge must fit inside/outside the feature, the NO GO gauge must not. If the GO gauge does not fit, the tolerance is above the maximum metal tolerance. If the NO GO gauge goes, the feature is below the minimum metal tolerance.
· This method is best suited to unskilled operators testing many parts, although more modern quality methods suggest this procedure should be replaced with Statistical Process Control (SPC).
· This method can also be used for inspection rooms, and limited runs using gauge blocks.