Instrument: Mass Spectrometer
General term for instruments used to measure the mass-to-charge ratio of ions; generally used to find the composition of a sample by generating a mass spectrum representing the masses of sample components.
N2 excess were determined from N2/Ar ratios measured using the procedures described by Charoenpong et al. (2014) with the exception that the measurements were made at sea using a Pfieffer 400 series quadrupole mass spectrometer system.