When this registry entry is set to TRUE (1), the contact probe tip diameter is not updated based on the measurements taken with the ring tool. You want this value to be TRUE (1) when a sphere tool is being used for tip diameter calibration instead of a ring.
Entry Name: ProbeQualRingDontUpdateTipDiameter
Entry Type: Whole number that specifies TRUE (1) or FALSE (0). The default value is 0.