A Method to Measure the Dynamic Characteristics of Microhumidity Sensors

Abstract

The method of measuring the dynamic characteristics of microhumidity sensors is becoming a bottleneck in developing fast-response humidity sensors. This paper introduces a method for measuring the dynamic characteristics of microhumidity sensors. In this method, two environments with different relative humidity (RH1 and RH2) are established using different saturated aqueous solutions of salt. There is independent air circulation for each environment. These loops of air circulation are connected to the test cell, where the tested sensor is located. Air coming from the RH1 environment always flows over the tested sensor until the valves controlling the air circulation of the RH2 environment operate. Then, the air humidity of the test cell is quickly changed from RH1 to RH2. By decreasing the time needed to change the humidity of the air in the test cell, the response time of the tested sensor can be obtained more precisely. A prototype based on this method is built, and it is tested by measuring the dynamic behavior of a parallel plate capacitance humidity sensor based on polyimide. The analytical results show that the response time of the prototype is less than 250 ms. The response time of the prototype can be improved greatly by enhancing the response time of the subassemblies used in the prototype.

Low-power wireless system for temperature and humidity monitoring in artificial ventilation

“…They are considered passive conditioners because they do not require an external power supply to system, but we do not found the realized instrument. Different other systems and methods are reported in the literature for similar applications [10], [11]. However, several aspects are not completely covered, such as long monitoring, wireless transmission, low-power consumption and user-friendly interface.…”

Theoretical and Simulation Analysis of Static and Dynamic Properties of MXene-Based Humidity Sensors

“…Recently, the effects of sensor structures on humidity-sensing characteristics have been reported from various perspectives [9,12], but few works consider the effects of the film thickness. Since both capacitance and response time are related to thickness, thickness will inevitably affect the properties of the sensor [13,14]. During the past decade, a novel type of 2D transition metal carbide and carbon-nitrogen-labeled MXene families have been widely researched for their potential applications in humidity sensing, food analysis, clinical detection, and many other fields [15][16][17][18][19][20].…”