再谈四球试验中P_B、P_D与ZMZ的相关性

THE RELATIVITIES OF P_B,P_D AND ZMZ IN FOUR-BALL TEST

根据九个研究单位的270组原始测试数据，采用最小平方线性回归分析法，分别探讨了润滑剂承载能力PB、PD、1／2（PB＋PD）与ZMZ的相关关系。研究表明：PB与ZMZ、PD与ZMZ之间均有一定的相关性，而尤以1／2（PB＋PD）与ZMZ的相关性最为显著。通过统计学方法，本文提出了可按PD值选用的三个ZMZ计算公式，并由十四个试验室对其进行了验证试验，结果表明，在置信水平为95％的条件下，采用GB／T3124法与采用本方法所得到的ZMZ值是一致的。

Based on the 270 series original test data from nine research units, the relativities between ZMZ and PB, PD, 1/2 (PB + PD) were studied by adopting the minimum square linear regression analysis, it's found that the relativities are good, especially the last one. Three formulas of calculating ZMZ according to PB and PD are put forward in the light of statistics method, when PD is in different range, different formula should be chosen. They were verified by fourteen laboratoriesThe results are equality between calculating ZMZ by using statistics method and testing ZMZ by using GB/T3142 method in 95% confidence level