当前,在育林作业和伐区调查设计中,特别需要测定各材种的小头直径,来计算各材种出材量的数字。而各材种小头直径的测定,一般都采用伐倒木和爬树的办法,按材种长度实际量取来测定的。这样的做法,不仅费工、费时,而且也会给经济上造成很大的浪费,如果能用一种简单的测径工具,把立木(按材种高度)小头直径直接测定出来。达到速度快、质量高、测定准确,那就会 At present, in the field of silviculture and cutting survey design, in particular, the need to determine the diameter of each species of small head, to calculate the number of each species of wood. The determination of the small diameter of the species, the general method of cutting down trees and trees, according to the actual length of the material taken to determine. This is not only labor-intensive and time-consuming, but it also causes great economic waste. If a simple diameter measuring tool can be used, the diameter of the stubble (at the height of the timber) can be measured directly. Achieve fast, high quality, accurate measurement, it will