Palma Alberto J, López-González Javier, Asensio Luis J, Fernández-Ramos María Dolores, Capitán-Vallvey Luis Fermín
Department of Electronics and Computer Technology, University of Granada, E-18071 Granada, Spain.
Anal Chem. 2007 Apr 15;79(8):3173-9. doi: 10.1021/ac062246d. Epub 2007 Mar 17.
This report addresses the task of calibrating an optical sensor for oxygen determination. Detailed analyses of the functional dependences from our measurement system results have been carried out with the additional aim of temperature compensation. As a result, an empirical calibration function has been successfully derived for the luminescent quenching-based oxygen sensor included in a self-designed portable instrument. This function also compensates for the temperature influence on the quenching luminescence process in the range from 0 to 45 degrees C. Moreover, the calibration procedure is extremely simple because only a single standard is needed. In fact, the oxygen measurement system can be calibrated with exposure to an open air atmosphere, and therefore, neither laboratory standards nor trained personnel are required. The method has been applied to a set of 11 units of the mentioned sensor (up to 24% oxygen concentration) giving an overall deviation between our calibrated system results and the laboratory standards of 0.3% oxygen concentration (calculated with 95% confidence level). The proposed calibration function has shown itself to be applicable for different sensing film thicknesses and luminophore concentrations using the same fittings parameter. Additionally, this function has been successfully applied to other oxygen dyes. Good agreement has also been found when the performance of the instrument was compared to a commercially available portable instrument based on an electrochemical sensor. We believe that this work could be an interesting finding for spreading the use of optical sensors for atmospheric oxygen determination in commercial measurement equipment for different purposes in confined working atmospheres, such as mines, undergrounds, warehouses, vehicles, and ships.
本报告阐述了校准用于测定氧气的光学传感器的任务。基于温度补偿这一额外目标，对我们测量系统结果的函数依赖关系进行了详细分析。结果，针对自行设计的便携式仪器中包含的基于发光猝灭的氧气传感器，成功推导了一个经验校准函数。该函数还能在0至45摄氏度范围内补偿温度对猝灭发光过程的影响。此外，校准过程极其简单，因为仅需一个标准即可。实际上，氧气测量系统在暴露于露天大气的情况下即可校准，因此既不需要实验室标准，也不需要专业人员。该方法已应用于11个上述传感器（氧气浓度高达24%），校准系统结果与实验室标准之间的总体偏差为0.3%氧气浓度（以95%置信水平计算）。所提出的校准函数已证明，使用相同的拟合参数，它适用于不同的传感膜厚度和发光团浓度。此外，该函数已成功应用于其他氧染料。将该仪器的性能与基于电化学传感器的市售便携式仪器进行比较时，也发现了良好的一致性。我们认为，这项工作对于在诸如矿山、地下场所、仓库、车辆和船舶等受限工作环境中用于不同目的的商业测量设备中推广使用光学传感器来测定大气中的氧气而言，可能是一项有趣的发现。
