With an initial concentration of 100 ppmv, the area amounts to 100.08 m/s-s with the hand injection and to about 772.63 m/s-s with the use of a PC-device. This means that the peak caused by 100 ppmv with the use of the PC-device is about 7.7 times higher. But, the amount of ethylene that passes the PC
during adsorption with a flow rate of 10 sccm and an adsorption time of 22 min is about 22 times higher. Another interesting observation is that the peak-area caused by 400 ppbv is about 18 times smaller than the peak-area caused by the initial concentration of 100 ppmv of ethylene. However, it
should be 250 times smaller according to the concentration. This means that the preconcentration factor increases dramatically with the decrease of the ethylene concentration and for 400 ppbv, in comparison to 100 ppmv, it is 14 times better than predicted. A conclusion is that the adsorption capabilities strongly depend on flows through the GC and several compounds get separated from each other. Thereby, they cause output signals on the gas sensor and the humidity sensor at different times. During the measurements
the GC is constantly heated and maintained at a temperature of 45◦C