Inaccuracies in survey data attributable to “the luck of the drawin creating a probability sample.在产生概率抽样时由于抽样不足而造成的数据偏差.
METRAwin 10/50 software sets measuring function parameters, transmits data and represents them in graphic (Yt and XY gra50台式万用表的分析和记录软件可设置测量功能参数，传输数据，可以图形和表格形式进行表述。