For developing low emission vehicles, the understanding of the variations in the composition of hydrocarbons is very important. In conventional methods for analyzing specific hydrocarbons during engine operation, exhaust gases have been sampled with gas-sampling bags and analyzed using gas chromatography ( GC ), one after another. Because of long sampling duration, these methods are not adequate to analyze the emission change in the transient state of engine operation.

Therefore, a quick sampling GC system was developed by combining a new analytical method for analyzing specific hydrocarbons ( described in Part 1 ) with a new time-resolved sampler.

This sampler is applicable to analysis of specific hydrocarbons in very short duration in the transient state of engine operation.

The time-resolved sampler consists of 6 sample tubes kept at a constant temperature, computer-controlled switching valves with pneumatic actuators, a sample suction pump and a sample feeder with helium gas. A glass-lined stainless steel tube is used in the sample tubes, which makes it possible to stably store hydrocarbons. The time-resolved sampler is capable of quick sampling of exhaust gases for the duration as short as 0.2 seconds and of stable storing of the gases for 10 hours.

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