Mass spectrometer is an analytical instrument that measures the mass-to-charge ratio of ions. The results are presented as a mass spectrum, a plot of intensity as a function of the mass-to-charge ratio.
Analyzed gas, normally a tracer gas such as Helium, Hydrogen or SF6 are ionized in vacuum. Ions of the gas are accelerated using added voltage and further separated in the magnetic field. The ion current has a detector turned into an electric current. The current is accelerated and displayed on the screen using leak detection units. The measured current is in direct proportion to helium concentration resulting in the measured leak.
Mass Spectrometer is an essential instrument in leak testing machines with requirements for detection of small leaks.