自从1993年开始，水稻化验标准由省标改为国标，由于省标与国标的要求不同，导致同一批水稻出品率有一定变化，现就其变化的主要原因及变化情况介绍如下。一、检验完善粒含量和不完善粒含量所用的试样不同。国标所用试样为净稻谷（净稻谷为从平均样品中不加选择地拣出的稻谷粒 Since 1993, the standard for testing rice has been changed from the provincial standard to the national standard. Since the requirements of the provincial standard and the national standard are different, the output rate of the same batch of rice is subject to some changes. The main reasons for the changes and their changes are as follows. First, the test to improve grain content and imperfect grain content of the sample used in different. National standard samples used for the net rice (net rice as the average sample from the indiscriminate pick out of rice grains