MC-21-B高精度电阻箱初步测试

时间：2022-09-06 03:00:00 高精度高精度电阻100

00测试背景

在 电阻箱TB购买地址 委托白超¹今天购买的高精度大范围电阻箱到货。准备使用 RIGOL DM3068数字万用表测量各电阻档的读数值。

^{▲ 大范围电阻箱的外观}

测量条件：直接将DM3068的表笔使用自配的鳄鱼嘴夹加在电阻箱的各个单位上。读出对应的输出数值。

02测试结果

1.档位0.1Ω 至 100欧姆

0	1	2	3	4	5	6	7	8	9
0.073202	0.172580	0.276735	0.374724	0.495532	0.583525	0.683493	0.777082	0.876624	0.983649
0.075313	1.097317	2.103899	3.103221	4.081541	5.075538	6.092531	7.085583	8.116869	9.069263
0.097105	10.140467	20.145667	30.181984	40.240051	50.156748	60.207994	70.231826	80.142315	90.140258
0.132334	100.185458	200.330008	300.415771	400.469343	500.730170	600.347544	700.868666	800.775055	899.516955

2. 档位100Ω至10M欧姆

0	1	2	3	4	5	6	7	8	9
0.268212	1000.327780	1999.750190	3000.467940	4004.473500	5003.164830	6011.004270	7004.775120	8007.018600	9009.039110
0.285563	10007.109400	20005.343500	30000.390000	40034.609000	50074.951300	60056.049900	70103.841600	80165.789500	90111.202100
0.263665	100140.118000	200619.097000	300903.150000	400805.849000	500934.520000	601106.300000	701418.194000	801333.482000	903197.913000
0.313406	1003429.380000	2008771.050000	3011882.740000	3996829.320000	5017496.790000	5998610.980000	6997175.550000	8009518.410000	8982766.300000
0.320662	9982007.260000	20036654.800000	29977984.200000	40102427.900000	49685229.600000	59888626.600000	70171662.700000	79947291.100000	89536774.200000

3.超出量程

对于100M超过上述范围的电阻超过了上述范围DM测量范围为3068。

03结果分析

假设某一组电阻测量结果如下： $R_n = [r_0 ,r_2 , \cdots ,r_9 ]$

则对应的递增相对误差为：
$\eta _i = { {r_{i + 1} - r_i } \over {R_{group} }} \times 100\% ,\,\,\,\,i = 0,1, \cdots 8$

其中 $R_{group}$ 是该组测量电阻的档位。

1.低档位的电阻相对误差

^{▲ 0.1~100Ω递增相对误差}

2.高档位的电阻相对误差

^{▲ 1k~10M递增相对误差}

#!/usr/local/bin/python
# -*- coding: gbk -*-
#============================================================
# TEST1.PY -- by Dr. ZhuoQing 2020-09-23
#
# Note:
#============================================================

from headm import *

res0 = [0.073202, 0.17258, 0.276735, 0.374724, 0.495532, 0.583525, 0.683493, 0.777082, 0.876624, 0.983649]
res1 = [0.075313, 1.097317, 2.103899, 3.103221, 4.081541, 5.075538, 6.092531, 7.085583, 8.116869, 9.069263]
res2 = [0.097105, 10.140467, 20.145667, 30.181984, 40.240051, 50.156748, 60.207994, 70.231826, 80.142315, 90.140258]
res3 = [0.132334, 100.185458, 200.330008, 300.415771, 400.469343, 500.73017, 600.347544, 700.868666, 800.775055, 899.516955]

resh0 = [0.268212, 1000.32778, 1999.75019, 3000.46794, 4004.4735, 5003.16483, 6011.00427, 7004.77512, 8007.0186, 9009.03911]
resh1 = [0.285563, 10007.1094, 20005.3435, 30000.39, 40034.609, 50074.9513, 60056.0499, 70103.8416, 80165.7895, 90111.2021]
resh2 = [0.263665, 100140.118, 200619.097, 300903.15, 400805.849, 500934.52, 601106.3, 701418.194, 801333.482, 903197.913]
resh3 = [0.313406, 1003429.38, 2008771.05, 3011882.74, 3996829.32, 5017496.79, 5998610.98, 6997175.55, 8009518.41, 8982766.3]
resh4 = [0.320662, 9982007.26, 20036654.8, 29977984.2, 40102427.9, 49685229.6, 59888626.6, 70171662.7, 79947291.1, 89536774.2]

err0 = [(x1-x2)*0.1 for x1,x2 in zip(resh0[1:], resh0[:-1])]
err1 = [(x1-x2)*0.01 for x1,x2 in zip(resh1[1:], resh1[:-1])]
err2 = [(x1-x2)*0.001 for x1,x2 in zip(resh2[1:], resh2[:-1])]
err3 = [(x1-x2)*0.0001 for x1,x2 in zip(resh3[1:], resh3[:-1])]
err4 = [(x1-x2)*0.00001 for x1,x2 in zip(resh4[1:], resh4[:-1])]
plt.plot(err0, label='1k')
plt.plot(err1, label='10k')
plt.plot(err2, label='100k')
plt.plot(err3, label='1M')
plt.plot(err4, label='10M')

plt.xlabel("Sample")
plt.ylabel("Error(%)")
plt.grid(True)
plt.legend(loc="upper right")
plt.tight_layout()
plt.show()

#------------------------------------------------------------
# END OF FILE : TEST1.PY
#============================================================

04结论

利用万用表对于购买得到的大量程电阻箱进行精度测试，测试了各个档位的具体电阻值以及相应的误差分布。

通过测量结果来看，电阻箱的范围是足够大，读出精度低于不犹豫5%。这个精度的确堪忧。

^{▲ 电阻箱外观}

■ 相关文献链接:

学校教学器材教具实验室用具标准电阻箱电子专业可调电阻箱999MΩ-淘宝网

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MC-21-B高精度电阻箱初步测试

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