煤炭采样机偏倚试验中最大允许偏倚(B)的研究

Study on the maximum tolerable bias(B) in mechanical coal sampler's performance testing for bias

对煤炭采样机偏倚试验中最大允许偏倚（B）进行了研究．通过实测和分析得出，最大允许偏倚对于精煤为0．50％，其它洗煤为0．80％；对于灰分Ad〈15％，15％～30％以及〉30％的筛选煤分剐为0．80％，1．10％和1．50％；对于灰分Ad〈15％，15％～30％以及〉30％的原煤分别为1．00％，1．30％和1．80％．该B值不仅是采样机偏倚试验的性能判据，实为适合我国煤炭品质均匀性的机械化采样最大允许系统误差，同时也为手工采样的系统误差提供了参考．

Studied the the maximum tolerable bias（B）in mechanical sampler＇s performance testing for bias. The conclusions are as follows through determination and theoretic analysis of bias： B is 0. 50 % for cleaned coal, 0. 80 % for washed coal; 0. 80 % , 1.10 % and 1.50 % for screened coal of ash value in dry basis less than 15 % , between 15% and 30 % , and higher than 30 % , respctively; 1.00 % , 1.30 % and 1.80 % for raw coal of ash value in dry basis less than 15 % , between 15 % and 30 % , and higher than 30 % , respctively. The above B value is both performance criterion in mechanical sampler＇ s bias testing, and is mechanical sampling＇ maximum systemic error to be permitted. In addition, the study affords reference for manual sampling.