There are several different measurement test data types that can be included on a calibration certificate, the primary ones being: “As Found” or “Before” Data: Calibration data that is documented during the calibration and before the unit is adjusted and/or repaired. This data is critical to support any necessary customer investigation in the event that Out of Tolerance conditions are detected during the calibration. “As Left” or “After” Data: Calibration data that is documented during the calibration performed after the unit is adjusted and/or repaired.