A family of quadrupole mass spectrometers designed specifically for UHV/XHV performance is available from Hiden Analytical Ltd. Evolved from the company’s 3F-series concept, the instruments incorporate triple-stage mass filter technology for optimum mass separation, ion transmission efficiency and contamination resistance. All systems feature the Windows-MASsoft Pro control program with multiparameter scanning. Ion detection is measured by fast pulse counting with continuous seven-decade scaling from 1 c/s to 1 x 107 c/s. Sampling rates exceed 500 measurements per second, with partial pressure detection down to 5 x 10—15 mbar and trace level detection to 5 ppb. Applications include laser ablation, thermal desorption, molecular beam and general neutrals studies.