Gain Adjustment for Signal-to-Noise Ratio Improvement in Electrical Capacitance Tomography System EVT4

被引：50

作者：

Kryszyn, Jacek ^{[1
]}

Wanta, Damian M. ^{[1
]}

Smolik, Waldemar T. ^{[1
]}

机构：

[1] Warsaw Univ Technol, Fac Elect & Informat Technol, Div Nucl & Med Elect, PL-00665 Warsaw, Poland

来源：

IEEE SENSORS JOURNAL | 2017年 / 17卷 / 24期

关键词：

Electrical capacitance tomography; capacitance measurement; integrator; signal-to-noise ratio; DATA-ACQUISITION SYSTEM; SENSOR; DESIGN;

D O I：

10.1109/JSEN.2017.2744985

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

A very small value of inter-electrode capacitance is a main factor limiting image spatial resolution of electrical capacitance tomography. The front-end sensing circuit of multi-channel capacitance tomography system EVT4 was designed for measurement of extremely small capacitance values in the range from 1 fF to several pF. The capacitance value is determined by charging it using a single high voltage pulse and integrating a charging current. The idea of gain adjustment in the front-end amplifier of a capacitance measurement circuit is presented. The switchable feedback loop of the inverting preamplifier-a first stage of the sensing circuit-enables gain adjustment in a wide range. The measurements using a cylindrical 2-D capacitance sensor were performed without and with gain adjustment. The obtained results showed improvement of signal-to-noise ratio for the pairs of opposite electrodes from about 22 to 30 dB.

引用

页码：8107 / 8116

页数：10

共 29 条

[1] Electrical capacitance tomography - Sensor models, design, simulations, and experimental verification [J].