S Spectrometer for Direct Sampling of Atmospheric Gases and Condensation Products,Lin,Sin-Shong ;AMMRC-TR-73-9DA-1-T-061102-B-13-A(*gas analysis, *mass spectroscopy), design, laboratory equipment, atmospheres*quadrupole mass spectroscopyAn apparatus for sampling atmospheric gases and condensation products has been designed and fabricated. A quadrupole mass spectrometer and modulated beam technique were used for beam detection. The design detail and the system performance are described and results are briefly presented. The sensitivity of the sampling device researches reaches parts per million, and numerous large clusters and aggregates generated from supercooling of gases during sampling processes were detected.