Zubair Muhammad, Tang Tong Boon
Department of Electrical and Electronic Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750, Tronoh, Perak, Malaysia.
Sensors (Basel). 2014 Jun 25;14(7):11351-61. doi: 10.3390/s140711351.
This paper presents the design of a non-intrusive system to measure ultra-low water content in crude oil. The system is based on a capacitance to phase angle conversion method. Water content is measured with a capacitance sensor comprising two semi-cylindrical electrodes mounted on the outer side of a glass tube. The presence of water induces a capacitance change that in turn converts into a phase angle, with respect to a main oscillator. A differential sensing technique is adopted not only to ensure high immunity against temperature variation and background noise, but also to eliminate phase jitter and amplitude variation of the main oscillator that could destabilize the output. The complete capacitive sensing system was implemented in hardware and experiment results using crude oil samples demonstrated that a resolution of ± 50 ppm of water content in crude oil was achieved by the proposed design.
本文介绍了一种用于测量原油中超低含水量的非侵入式系统的设计。该系统基于电容到相角转换方法。含水量通过一个电容传感器进行测量，该传感器由安装在玻璃管外侧的两个半圆柱形电极组成。水的存在会引起电容变化，进而相对于主振荡器转换为相角。采用差分传感技术不仅是为了确保对温度变化和背景噪声具有高抗干扰能力，而且是为了消除可能使输出不稳定的主振荡器的相位抖动和幅度变化。完整的电容传感系统通过硬件实现，使用原油样品的实验结果表明，所提出的设计实现了原油含水量±50 ppm的分辨率。
