基于自动平衡桥的广泛阻抗频谱测量,考虑Op-Amp输入阻抗
Yuxiong Cai1, Xuanze Wang2, Xin Yu1
1Hubei Key Laboratory of Modern Manufacturing Quantity Engineering, School of Mechanical Engineering, Hubei University of Technology, Wuhan, China.
The Review of scientific instruments
|October 9, 2023
概括
本研究介绍了一种两步激发方法 (TSEM) 和增量代方法 (IIM),通过解决操作放大器 (Op-Amp) 输入阻抗效应来改进高阻抗测量. 这些方法提高了在广泛范围内的阻抗测量的准确性.
科学领域:
- 电气工程 电气工程
- 计量学 计量学 计量学
- 仪器化 仪器化 仪器化
背景情况:
- 用于高阻抗测量的自动平衡桥梁中的操作放大器 (Op-Amps) 受其输入阻抗的影响,影响了准确性.
- 现有的方法与低分辨率DAC和低频漂移造成的扭曲作斗争,限制了测量精度.
研究的目的:
- 为高阻抗测量提出和验证一种新的两步激发方法 (TSEM) 和增量代方法 (IIM).
- 通过减轻Op-Amp输入阻抗效应和信号扭曲,提高阻抗测量的准确度和精度.
主要方法:
- 开发了一种两步激发方法 (TSEM) 来确定测试值下的Op-Amp输入阻抗和初始装置.
- 实施了一种增量代方法 (IIM),使用TSEM结果实现快速桥梁平衡.
- 设计了一个可编程增益放大器来解决DAC扭曲,并使用半循环差异算法来减轻DC漂移.
主要成果:
- 在 1-100 kHz 频率范围内,从 1 kΩ 到 100 MΩ 的阻抗测量得到了 1 MΩ 的参考阻抗.
- 证明了高精度,模量相对标准偏差 (RSD) < 0.384%和相角标准偏差 (SD) < 3.49 mrad.
- 对于 1 MΩ 阻抗的特殊精度:RSD < 0.006% 和 SD < 0.1 mrad.
结论:
- 拟议的TSEM和IIM有效地克服了由Op-Amp输入阻抗引起的高阻抗测量的局限性.
- 综合技术显著提高了在广泛的阻抗和频率范围内测量的准确性和精度.
- 这种方法为各种科学和工程应用中精确的高阻抗表征提供了强大的解决方案.
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