Continuous determination of condensable hydrocarbons in e.g. motor fuel

摘要

The sample gas stream, including condensables, is introduced hot into the flame ionization detector (12). Another stream of this gas is passed through a suitable filter (9), to separate the condensables, before reaching the detector. Two defined sample loops (5) are filled simultaneously. The gas contained, is led to the detector in a stream of carrier gas (8), in succession by use of selector valves. The entire apparatus (11) up to the condenser section and filter, is heated to a sufficient temperature to prevent condensation of the hydrocarbons being measured. For each sample path a detector is provided; both sample volumes can be flushed simultaneously to the respective detector. There are a number of heated filters, switched by valves. Each filter not in use, is regenerated by heating and back-flushing with carrier gas. A control unit operates the valves, also recording and evaluating the measured signals.