自动检测技术-许大宇-作业解答
第一章 作业
对某节流元件(孔板)开孔直径d20进行了15次测量,测量数据如下(单位:mm) 120.42 120.43 120.43 120.41 120.40 120.43 120.42 120.42 120.43 120.39 120.39 120.40 120.30 120.39 120.40 试用格拉布斯准则判断上述数据是否含有粗大误差,并写出其测量结果。 解: Di 120.42 120.43 120.4 120.42 120.43 120.39 120.3 120.4 120.43 120.41 120.43 120.42 120.39 120.4 120.39 vi 0.016 0.026 -0.004 0.016 0.026 -0.014 -0.104 -0.004 0.026 0.006 0.026 0.016 -0.014 -0.004 -0.014 vi2 0.000256 0.000676 1.6E-05 0.000256 0.000676 0.000196 0.010816 1.6E-05 0.000676 3.6E-05 0.000676 0.000256 0.000196 1.6E-05 0.000196 vi’ 0.008571 0.018571 -0.01143 0.008571 0.018571 -0.02143 -0.01143 0.018571 -0.00143 0.018571 0.008571 -0.02143 -0.01143 -0.02143 vi?2 7.34694E-05 0.000344898 0.000130612 7.34694E-05 0.000344898 0.000459184 0.000130612 0.000344898 2.04082E-06 0.000344898 7.34694E-05 0.000459184 0.000130612 0.000459184
d??dii?115 15?120.404 ?1?15?vi?12i152i ?2?14?v?ii?12i142n?1n?115?1?0.032689G?1?2.7*0.032689?0.08826v7?0.08826,d7应剔去新平均值:d??120.4114 算术平均值的标准差为:
??vi?114?1?0.0161G?2?2.66*0.0161?0.0428均符合要求??v?i?1 ???2?0.004314
d20?d?Z??120.4114?3?0.0043?120.4114?0.0129
用手动平衡电桥测量电阻Rx,已知R1=100Ω,R2=1000Ω,RN=100Ω,各桥臂电阻的恒值系统误差分别为△R1=0.1Ω,△R2=0.5Ω,△RN=0.1Ω。求消除恒值系统误差后的Rx值。 解:
Rx?R1RNR2
R1RN100?100??10R21000 ?Rx?R?R?R1?x?R2?x?RN?R1?R2?RNRx0??Rx???RNRRR?R1?12N?R2?1?RNR2R2R2100100?100100?0.1??0.5??0.12100010001000?0.015