Over time you may notice matter building up in the barrels of the scanner. To clean this out we recommend using compressed air and if necessary a moist Q-Tip. A side from keeping your scanner free from debris you can call Titronics and schedule a recalibration. It is recommended that you send your scanner in to Titronics for recalibration every 1-2 years to ensure that the scanner is calibrated and as finely tuned as possible.