A sensor calibration is necessary. The Label Sensor must be calibrated to the specific label stock being used for each memory location. Use the following procedure to calibrate the applicator for your specific label stock/liner material or you may watch this AP550 Calibration Video.1. Load the label stock as described in Section 2. Be sure to remove labels from the liner back to the Liner Drive Roller. For reflective stock, the black mark should be positioned directly under the Label Guide Roller. The goal is to feed only clean liner through the sensor area. This will give the sensor a good reading of the liner material. 2. Once the liner is loaded, follow the steps above to navigate to the SC- setting in the Setup Mode.3. Lower the arm to trigger the calibration.4. The label stock will move forward until the first label is presented for application.5. Calibration for this liner is now complete and the values are stored in the current memory location.Note: It is not necessary to recalibrate the label sensor between rolls of the same label stock.