KEHWS-900S temperature vapor sampling devices installed in the system, highefficient cooler cooling the sample after the sample temperature dropped below 40 ℃,but not yet meet the requirements of the sampling instrument (25 ℃ ± 1 ℃).Thermostat temperature of the sample can be controlled at low temperature 25 ℃ ± 1 ℃ range of instruments to further improve measurement accuracy.