U.S. Army Combat Capabilities Development Command Chemical Biological Center, 5198 Blackhawk Road, Aberdeen Proving Ground, MD, 21010, USA.
Sci Rep. 2022 Jan 10;12(1):408. doi: 10.1038/s41598-021-04073-2.
Generation and control of humidity in a testing environment is crucial when evaluating a chemical vapor sensor as water vapor in the air can not only interfere with the sensor itself, but also react with a chemical analyte changing its composition. Upon constructing a split-flow humidity generator for chemical vapor sensor development, numerous issues were observed due to instability of the generated relative humidity level and drift of the humidity over time. By first fixing the initial relative humidity output of the system at 50%, we studied the effects of flowrate on stabilization time along with long term stability for extended testing events. It was found that the stabilization time can be upwards of 7 h, but can be maintained for greater than 90 h allowing for extended experiments. Once the stabilization time was known for 50% relative humidity output, additional studies at differing humidity levels and flowrates were performed to better characterize the system. At a relative humidity of 20% there was no time required to stabilize, but when increased to 80% this time increased to over 4 h. With this information we were better able to understand the generation process and characterize the humidity generation system, output stabilization and possible modifications to limit future testing issues.
在评估化学蒸气传感器时，生成和控制测试环境中的湿度是至关重要的，因为空气中的水蒸气不仅会干扰传感器本身，还会与化学分析物发生反应，改变其组成。在为化学蒸气传感器开发构建分流式湿度发生器时，由于生成的相对湿度水平不稳定以及湿度随时间漂移，观察到了许多问题。首先将系统的初始相对湿度输出固定在 50%，我们研究了流速对稳定时间以及扩展测试事件的长期稳定性的影响。结果发现，稳定时间可能长达 7 小时以上，但可以维持 90 小时以上，从而可以进行扩展实验。当知道 50%相对湿度输出的稳定时间后，在不同的湿度水平和流速下进行了进一步的研究，以更好地描述该系统。在相对湿度为 20%时，不需要稳定时间，但当增加到 80%时，稳定时间增加到 4 小时以上。有了这些信息，我们就能更好地了解生成过程并描述湿度生成系统、输出稳定以及可能的改进措施，以限制未来的测试问题。
