<正>烟雾机是森林病虫害防治中的主要设备之一，燃烧室－喷管是烟雾机的主要部分。笔者对燃烧室－喷管工作频率的理论计算方法进行细致的分析与推导，并结合实际进行了试验验证。

A fogger in one of main devices used in forestry disease and insect control. A combustion chamber and exhaust tube(C.E.T.) is one of the main units of a fogger. The theoretical formula of calculating pulsating frequency of a C.E.T. is analyzed and deduced in the paper. It is proved that the test data of pulsating frequency of a C.E.T. will meet accurately the result calculated from the formula which provides the theoretical basis for C.E.T. designing.