Calibration
"CAL" indicator and "ERROR" indicator in the display
Cause: The calibration of the grade measurement was not carried out in the correct order or in the correct positions
Corrective measure: Repeat the calibration according to the instructions on the display and in the operating manual
Cause: The surfaces used for calibration were not exactly aligned on a horizontal or vertical level
Corrective measure: Repeat the calibration on a horizontal or vertical surface and check the surfaces beforehand, if necessary, using a spirit level
Cause: The measuring tool was moved or tilted when pressing the button
Corrective measure: Repeat the calibration and hold the measuring tool still on the surface while pressing the button