How to locate vacuum leaks in an Agilent 5977 Mass Selective Detector (MSD) using electronics duster and Manual Tune. In this hands-on tutorial, I demonstrate how to use duster gas to help identify vacuum leaks in a GC/MS system. The procedure involves monitoring the mass spectrum in Manual Tune while applying duster gas near suspected leak locations. Changes in the detected ions can help identify where air is entering the vacuum system. Vacuum leaks can affect instrument per