森林调查测树工具,如轮尺、卷尺、测高器等长期在野外使用,容易产生误差,为了确保调查质量,应该定期检验。工具、仪器产生的误差属非抽样误差,即使全林实测也会存在。因此,这种误差是抽样误差以外、未统计到计算精度内的一项误差。当这种误差数值较大时,会使调查的统计精度与实际不符,不单严重影响调查质量,还将影响分析得出的各种结论。使用未经检验的工具,难免有误差,有时可达观测值的3％以上。我们知道,在抽样调 Forest survey tree measuring tools, such as calipers, tape measure, height gauge and other long-term use in the field, prone to error, in order to ensure the quality of the survey should be regularly tested. Tools, instruments produce errors are non-sampling error, even if the whole forest measured there will be. Therefore, this error is outside the sampling error, not counting the calculation accuracy of an error. When this kind of error is large, the statistical accuracy of the survey will be inconsistent with reality, which will not only seriously affect the quality of the survey, but will also affect various conclusions drawn from the analysis. Using untested tools inevitably has errors, sometimes up to 3% or more of the observed value. We know that in the sample transfer