Gas Chromatography - Tandem Techniques - Introduction > Historical Development of GC Spectroscopy Systems > Page 4
After Banner et al. (Ref 3)
Figure 2. The Basic Design of the MS 12.
Considering the MS 12 was designed and produced in the late 1950s its specifications were quite impressive. The ion optical system was a 12 in. radius 90û sector magnetic analyzer with adjustable source and collector slits which ranged from 0.0003 to 0.03 in. The resolution at minimum slit widths was 2500 and at 0.004 in. 1000. Scanning from a mass range of 20 to 200 in 1 sec, the resolution was 200 (i.e. one mass unit)