QCM-based hygrometer sensors and evaluation of its performance in the presence of nanomaterials

In many key industries such as oil and gas, electronics, semiconductor, and food, measuring and controlling humidity is a critical and basic requirement. In these industries, moisture is a type of pollutant and leads to a significant reduction in product quality, equipment damage, and increased costs. The measurement variable is relative humidity, which expresses the amount of water vapor in the system as a fraction of the amount of moisture in the saturated state. On the other hand, absolute humidity is used more in the industry which is the mass of water vapor per unit volume of air will be at a certain temperature and pressure. Dew point is another common parameter of engineering sciences for measuring absolute humidity. The dew point indicates the amount of water vapor in the air stream and determines how to prevent condensation from forming. In recent years, quartz crystal sensors, due to their unique advantages, have attracted much attention for accurate and repeatable measurements of moisture and dew point. In this paper, a report on the mechanism of moisture absorption in these sensors in the presence of the studied nanomaterials will be presented.