Constant Split Ratio GC Flow Splitter for Splitting to FID and Mass Spectrometer

There are two common flow splitters in gas chromatography, unpurged and purged splitters. Unpurged splitters are simply a tee or "Y" fitting with the column flow split to two detectors. The purged splitter has the same three connections plus a connection for a makeup flow for pressure regulation at the splitter. The main deficiency of these splitters is a non-constant split ratio across the temperature program. This is due to the fact that the capillary restrictors for the two detectors each reside in a temperature programmed zone (GC oven) and a constant temperature zone (short zone within the FID and the transfer line to the mass spectrometer ion source).