Abstract：Aiming at the existing problems such as weak environmental adaptability, low analytic efficiency and poor measuring repeatability in the traditional spectral oil analyzers, the present paper designed a portable mid-infrared rapid analyzer for oil concentration in water. To reduce the volume of the instrument, the non-symmetrical folding M-type Czerny-Turner optical structure was adopted in the core optical path. With a periodically rotating chopper, controlled by digital PID algorithm, applied for infrared light modulation, the modulating accuracy reached ±0.5%. Different from traditional grating-scanning spectrophotometers, this instrument used a fixed grating for light dispersion and avoided rotating error in the course of the measuring procedures. A new-type MEMS infrared linear sensor array was applied for modulated spectral signals detection, which improved the measuring efficiency remarkably. Optical simulation and experimental results indicate that the spectral range is 2 800～3 200 cm-1, the spectral resolution is 6 cm-1 (@3 130 cm-1), and the signal to noise ratio is up to 5 200∶1. The acquisition time is 13 milliseconds per spectrogram, and the standard deviation of absorbance is less than 3×10-3. These performances meet the standards of oil concentration measurements perfectly. Compared with traditional infrared spectral analyzers for oil concentration, the instrument demonstrated in this paper has many advantages such as smaller size, more efficiency, higher precision, and stronger vibration&moisture isolation. In addition, the proposed instrument is especially suitable for the environmental monitoring departments to implement real-time measurements in the field for oil concentration in water, hence it has broad prospects of application in the field of water quality monitoring.
Key words：Spectrometer;MEMS;Linear sensor array;Mid-infrared;Oil in water
高志帆，曾立波，石 磊，李 凯，杨远洲，吴琼水* . 基于MEMS线阵的便携式中红外水中油浓度速测仪 [J]. 光谱学与光谱分析, 2014, 34(06): 1711-1715.
GAO Zhi-fan, ZENG Li-bo, SHI Lei, LI Kai, YANG Yuan-zhou, WU Qiong-shui* . Development of a Portable Mid-Infrared Rapid Analyzer for Oil Concentration in Water Based on MEMS Linear Sensor Array. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2014, 34(06): 1711-1715.
[1] Bobby P, Peter E, Andrew R. Environmental Science & Technology, 2007, 41(18): 6333. [2] Charef A, Ghauch A, Baussand P, et al. Measurement, 2000, 28: 219. [3] Jones Y K, Li Z H, Johnson M M, et al. IEEE Sensors J., 2005, 5(6): 1175. [4] FU Xiao-ran, ZHAO You-quan, FAN Shi-fu(傅潇然，赵友全，范世福). Modern Scientific Instruments(现代科学仪器), 2008, (5): 91. [5] Flavin K, Hughes H, Dobbyn V, et al. International J. Environmental Analytical Chemistry, 2006, 86(6): 401. [6] HJ 637—2012, Water Quality-Determination of Petroleum Oils and Animal and Vegetable Oils-Infrared Spectrophotometry. Beijing: China Environmental Science Press(北京：中国环境科学出版社), 2012. [7] MA Wen-li, XING Ting-wen, LI Hua(马文礼，邢廷文，李 华). Opto-Electronic Engineering(光电工程), 2004, 31(9): 41. [8] ZHANG Tie-qiang, LIN Xiao-long, SHEN Xuan-guo, et al(张铁强，林晓珑，申铉国，等). Chinese Journal of Scientific Instrument(仪器仪表学报), 1998, 19(5): 540. [9] LU Wan-zhen(陆婉珍). Modern Near Infrared Spectroscopy Analytical Technology(现代近红外光谱分析技术). Beijing: China Petro-chemical Press(北京：中国石化出版社), 2007. 107. [10] XIAO Jing-he, ZHAO Jian(肖景和，赵 健). Remote Circuits of Infrared Ray Pyroelectric and Ultrasonic Wave(红外线热释电与超声波遥控电路). Beijing: People Post and Telecommunications Press(北京：人民邮电出版社), 2003. 121. [11] WU Fei-die, JI Xin-ming, WANG Jian-ye, et al(吴飞蝶，纪新明，王建业，等). Acta Optica Sinica(光学学报), 2006, 26(7): 1097.
