As this third pulse approaches the tail of the second one it will also slow down (because the speed of light in the glass it is passing through has been reduced by the second pulse's passage).

Specially, the thermal lens effect is intensified due to the long tail attached to pulse, which leads to decreasing of conversion efficiency if pulse repetition rate is enhanced.

The shortcomings of general pulse technique, tail gas technique and stopped-flow technique in catalytic research might be overcome by using pulse catalytic chromatograph branch-flow technique.