Thermochemical Humidity Detection in Harsh or Non-Steady Environments.
Thermochemical Humidity Detection in Harsh or Non-Steady Environments.
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DOI：
10.3390/s17061196
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发表时间：
2017-05-24
期刊：
影响因子：
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通讯作者：
Forzani E
中科院分区：
文献类型：
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作者：
Bridgeman D;Tsow F;Xian X;Chang Q;Liu Y;Forzani E
我们提出了一种新的化学定量方法，利用热分析检测相对湿度。通过测量疏水改性的温度感测元件相对于疏水改性的参考元件的温度变化，可以测量来自感测元件中的化学相互作用的总热量，并将其用于计算相对湿度的变化。我们已经通过假设恒定温度流和恒定参考湿度（在这种情况下约为0%）来探索这个概念。这一概念已被探索与两种方法在这里提出：（1）基于晶闸管的方法和（2）热成像方法。对于第一种方法，使用了一种经过化学修饰的热敏电阻，并证明了0-75%相对湿度的检测范围。对于第二种方法，使用了一种经过化学修饰的一次性表面（传感元件）和热成像仪，并证明了不同相对湿度的热特征。这些新方法为化学条件恶劣的环境或快速变化的环境提供了机会。为了在化学条件恶劣的环境中感测湿度，经过化学改性的热敏电阻可以提供一种感测方法，消除金属触点的暴露，金属触点很容易被环境腐蚀。另一方面，热成像方法可以与一次性非接触式传感元件一起应用，这是在损坏或结垢不可避免的环境中的低成本维护选择。此外，对于快速变化的环境，热成像方法可能提供非常快速的湿度测量，因为化学相互作用是快速的，并且它们的变化很容易量化。
We present a new method of chemical quantification utilizing thermal analysis for the detection of relative humidity. By measuring the temperature change of a hydrophilically-modified temperature sensing element vs. a hydrophobically-modified reference element, the total heat from chemical interactions in the sensing element can be measured and used to calculate a change in relative humidity. We have probed the concept by assuming constant temperature streams, and having constant reference humidity (~0% in this case). The concept has been probed with the two methods presented here: (1) a thermistor-based method and (2) a thermographic method. For the first method, a hydrophilically-modified thermistor was used, and a detection range of 0–75% relative humidity was demonstrated. For the second method, a hydrophilically-modified disposable surface (sensing element) and thermal camera were used, and thermal signatures for different relative humidity were demonstrated. These new methods offer opportunities in either chemically harsh environments or in rapidly changing environments. For sensing humidity in a chemically harsh environment, a hydrophilically-modified thermistor can provide a sensing method, eliminating the exposure of metallic contacts, which can be easily corroded by the environment. On the other hand, the thermographic method can be applied with a disposable non-contact sensing element, which is a low-cost upkeep option in environments where damage or fouling is inevitable. In addition, for environments that are rapidly changing, the thermographic method could potentially provide a very rapid humidity measurement as the chemical interactions are rapid and their changes are easily quantified.