• Calibration shall be performed in an environment that conforms to Manufacturer Specifications. • The digital multimeter will hereafter be referred to as the Instrument Under Test (IUT). • Verify that the IUT is clean. • Visually examine the IUT for any condition that could cause errors in the calibration. • If any of the requirements cannot be met, refer to the applicable manufacturer manual. • If a malfunction occurs or a defect is observed while calibration is in progress, the calibration shall be discontinued and necessary corrective action taken; if corrective action affects a measurement function previously calibrated, the function shall be recalibrated before the remainder of the procedure implemented.