Development of O_2 and CO_2 measurement system for science education

在本研究中，我们开发了一个易于操作的O_2和CO_2测量系统，用于科学教育。我们使用一种易于制备的手工膜片原电池型传感器作为O_2传感器。这种O_2传感器不仅可以测量空气中的氧浓度，还可以测量溶液中的氧浓度，使其适合作为教育工具。我们使用固体电解质型传感器模块作为CO_2传感器。该系统采用O_2和CO_2传感器组合，实现了O_2和CO_2浓度的自动同时测量。我们还通过使用USB连接将传感器与PC连接，使用市售的电子表格软件开发了测量软件。最重要的优点是能够直观地看到不可见和无味的气体，如O_2和CO_2的浓度随时间的变化。我们用O_2和CO_2测量系统测量作者的呼气量，测量浅呼气量和深呼气量。首先，把更多吸入的空气呼进一个呼气袋。然后，深度吸入空气并保持30秒，然后呼出到袋子中。我们每隔5秒采样一次，并在90秒内测量每个样品的O_2和CO_2浓度。结果表明，浅呼气时的O_2浓度由20.8%降至18.6%。另一方面，CO_2浓度为17.8 ppm，明显高于大气CO_2浓度。深呼气时的O_2浓度由20.9%下降到16.8%，降幅约4.1%。另一方面，CO_2浓度为2.4 ppm。总之，任何人都可以很容易地测量浅呼气和深呼气中O_2和CO_2浓度随时间的变化，使用呼气袋和传感器系统。我们也可以很容易地进行实验，并获得高精度的数据。该传感器系统可以作为自然科学研究的教育工具，促进“生命”的基本概念。少

In this study, we developed an easy-to-operate O_2 and CO_2 measurement system for science education. We used an easily-prepared hand-made diaphragm galvanic cell-type sensor as the O_2 sensor. This O_2 sensor can measure not only the oxygen concentration in air, but also in a solution, making it suitable as an educational tool. We used a solid electrolyte-type sensor module as the CO_2 sensor.This system makes automatic and simultaneous measurements of O_2 and CO_2 concentration possible using the combination of the O_2 and CO_2 sensors. We also developed measurement software using commercially available spreadsheet software by connecting the sensor with a PC using a USB connection. The most important advantage is to be able to visualize the changes in the concentration of invisible and odorless gases such as O_2 and CO_2 as a function of time.We measured the author's expired air using the O_2 and CO_2 measurement system, measuring both shallow and deep expirations. First, shallowly i … More nhaled air is exhaled into an expiration bag. Then, air is deeply inhaled and held for 30 seconds before being exhaled into the bag. We sampled the air every 5 seconds and measured the O_2 and CO_2 concentration of each sample for 90 seconds.In respect to the results, the O_2 concentration in shallow expiration was decreased from 20.8% to 18.6%. On the other hand, the CO_2 concentration was 17, 8ppm, which was an increase the atmospheric CO_2 concentration. The O_2 concentration in deep expiration was observed to decrease by about 4.1% from 20.9% to 16.8%. On the other hand, the CO_2 concentration was 2, 4ppm.In conclusion, anyone can easily measure changes in the O_2 and CO_2 concentration as a function of time in shallow and deep expiration using an expiration bag and the sensor system. We can also carry out experiments easily and obtain highly accurate data. This sensor system can be expected to promote the basic concept of"Life"as an educational tool for the study of natural science. Less