Factory Calibration Clifton 27 point - measurements performed at 27 points (3 shelves fitted top, mid and bottom locations inside). Factory Calibration record must be ordered with equipment. Factory calibration record . The completed calibration record will be enclosed at the rear of the instruction book accompanying the Clifton unit carrying the following information: Unique record number for trace ability. Serial number of the unit. Instrument it was checked against. Calibration temperature and actual sensitivity results.