The Hiden HPR-20 TMS Transient MS is configured for fast event gas analysis of gases and vapors at pressures near atmosphere. Ideal for fast gas switching experiments the MS features the QIC quartz-lined 0.9 m sampling interface. The inlet, operating at 200 °C, provides response times of less than 150 ms to changes in gas composition with a 5 decade response time in < 200 ms. The QIC inlet is coupled directly to a Pulse Ion Counting (PIC) digital MS which is capable of measurement speeds of up to 500 data points/s over the entire 7 decade dynamic range.