Topas TDD590比较适合越来越多对热气体进行粒度分析的应用要求。对于此类测量，必须在不改变气溶胶粒径分布的情况下实现气体冷却。气化材料的冷凝过程会极大地影响粒径分布。

热扩散干燥器用于在发生冷凝成液滴之前去除汽化的气相。这种装置将气溶胶样品加热到与采样点相同的温度。加热后的气体流过充满活性炭的吸附管。在吸附部分内，蒸发的材料通过扩散运输过程在活性炭的表面被去除。初级气溶胶在吸附管内不受影响，因为与吸附材料没有直接接触。 thermodenuder tdd 590 根据此原理工作。管尺寸、气体加热器和微控制器控制的温度控制器专为高达 3 lpm 的气体流速而设计。温度可轻松调节至 400。

in increasing numbers of application particle size analysis in hot gases is requested. For such measurements a gas cooling must be realized without changing the particle size distribution of the aersol. particle size distribution can extremely affected by condesation processes of vaporised materials.

thermodenuders are used in order to remove the vaporised gas phase before ondensation to droplets occurs. such devices heat up the aerosol sample to the same temperature as at the point of sampling. the heated gas flows through an adsorption tube filled with active carbon. Inside the adsorption section vaporised materials are remobed at the surgace of activated carbon by means of diffusive transportation proesses. the primary aerosol is not affected inside the adsorption tube because there is no direct contact with the adsorptive material. the thermodenuder tdd 590 works according to this principle. The tube size ,gas heater and microporcessor controlled temperature controller are designed for gas flow rates up to 3 lpm. the temperature can be easil adjusted up to 400