The test result of the systems sampling resistance detection circuit

Release date:2017-06-30 The author：毫欧电子 Click on：

The test results of the system verify the sampling resistance circuit. Refer to "JJG L66 93 dc resistor" verification regulation, volt ampere method is used to calibrate it to verify whether the accuracy of the multi-function calibration system meets the design specifications. The adjustable constant current source provides the test current, the range is 0~600 A, and the current converter and voltmeter together make up the current measurement standard. The composition of the whole calibration scheme test system

采样电阻

The sampling resistance error is the actual sampling resistance value under different test current at 75 m Omega, and its relative error is less than 0.003%. Table 4 shows the error of simulating different resistance values of high power resistance when the fixed test current is 100 A. It can be seen from the table that the relative error is within 0.004%. This is because the device system uses such as DC comparator, differential amplifier, sampling signal amplifier, D/A converter is a high linearity element, high linearity system. It is proved that the accuracy of the system analog output resistance can be within 0.02% range and meets the design requirements after several tests and tests under different values and current.

表3 75mΩ在不同输入电流时的误差
实际电流/A	29.9996	40.0001	50.0001	59.9999	70.0008	80.0006	89.9995	100.0019
实际电阻/mΩ	74.9996	74.9977	75.0002	75.0002	74.9997	74.9992	75.0016	75.0015
误差/%	-0.0005	-0.003	0.0003	0.0003	-0.0004	-0.0010	0.0021	0.0019

表4 100A测试电流下不同电阻值的误差
模拟电阻/mΩ	7.5	22.5	30.0	45.0	60.0	67.5	75.0
实际电阻/mΩ	7.5003	22.5001	30.0011	45.0009	60.0006	67.5001	75.0015
误差/%	0.004	0.0004	0.0037	0.002	0.001	0.0001	0.0019

The block diagram of the calibration device for the sampling resistance multifunction calibration system. Data analysis, multi-functional calibration system calibration device for the system to calibrate the measurement. Current measurement error: Table 1 is relative error at different current tests under 20 A range, and the relative error is less than 0.011%. Relative error of the relative error at different current tests for 100 A range is less than 0.01%。

表1 20A量程下在不同电流测试时的误差
实际电流/A	4.0000	6.0000	8.00009	10.00002	12.0000	14.00004	15.99999	18.00000	20.00015
测量电流/A	3.9996	5.9996	7.9996	9.9996	11.9996	13.9996	15.9997	17.9997	20.0000
误差 /%	-0.0102	-0.0067	-0.0062	-0.0042	-0.0034	-0.0031	-0.0018	-0.0017	-0.0007

表2 100A量程下在不同电流测试时的误差
实际电流/A	29.9996	40.0001	50.0001	59.9999	70.0008	80.0006	89.9995	100.0019
测量电流/A	29.998	39.998	49.999	59.999	69.999	79.998	89.999	100.001
误差/%	-0.0054	-0.0052	-0.0022	-0.0014	-0.0026	-0.0033	-0.0006	-0.0009

Conclusion the design of multifunctional sampling calibration system for resistance tester simulation resistor in the traditional current mode active innovation, using precision simulation technology and high resistance current measurement technology, and three types of instrument verification device with a wide range of resistance value can be set up, which can simulate the continuous 1U ~3.75 arbitrary resistance value, the resolution of 10N. And 0.02 grade accuracy; test current range, up to 600 A and 0.02 level accuracy, related technical indicators have reached the domestic leading level in the industry, to meet the requirements of three kinds of test instruments, verification has been widely used on resistance tester in the loop resistance tester, DC resistance tester and grounding to guide the。