The sensitivity of the Skimmer coupling for combining the simultaneous thermal analysis (STA) method TG-DTA/DSC and mass spectrometry (MS) is further improved by a factor of three using an automatic vacuum control device. Especially high mass numbers are detected without the common condensation problems met in capillary couplings, as is shown by application of the skimmer coupling for coal, CuGaSe2-semiconductor material and polystyrene. The basic idea of the novel pulse thermal analysis technique (PTA) is demonstrated.