Design of an Acousto-Magnetic Oxygen Sensor

聲磁式氧氣感測器的設計

李俊翰(Jun-Han Lee) ； 蔡正倫(Cheng-Lun Tsai) ； 范棋翔(Chi-Shyan Fann) ； 王士豪(Shyh-Hau Wang)

《Journal of Medical and Biological Engineering》 22卷4期 (2002/12) Pp. 193-198

摘要

本研究的目的是以聲磁式原理建立一套氧氣檢測系統，由於氧分子具有順磁性會受到磁場的吸引，隨著交流磁場的變化，氧氣分子會來回震動產生音頻訊號，因此氧氣濃度可藉由量測C型電磁鐵所產生的聲磁訊號強度來檢測，此研究中並利用有限元素法模擬在電磁鐵間隙所產生之磁場強度與氧氣分子的受力分佈情形，在使用已知氧氣濃度的氣體樣本進行由0至100%濃度的校正實驗中，所得到的相關係數為0.9998，而在0%至20%濃度的校正實驗中，所得到的相關係數則為0.9951.

關鍵字

順磁性 ； 聲磁式 ； 氧氣濃度 ； 光纖式麥克風

並列摘要

The purpose of this study is to build an oxygen measurement system based on acousto-magnetic principle. Oxygen molecule can be attracted by a magnetic field due to its paramagnetic property. When oxygen molecules are driven by an alternative magnetic field, they vibrate and generate an acoustic signal. In consequence, the concentration of oxygen in the air can be measured by detecting the amplitude of acoustic pressure generated in the gap of a C-type electromagnet. Finite element analysis is also used to simulate the distribution of magnetic field intensity and force applied on oxygen molecules near the gap of electromagnet. The correlation coefficient of calibration using gases with known oxygen concentration is 0.9998 in the range from 0% to 100%. At the low concentration range, between 0% and 20%, the correlation coefficient is 0.9951.

並列關鍵字

Acousto-magnetic ； Oxygen concentration ； Paramagnetic ； Optical fiber microphone