The capability of capacitive sensors in the monitoring relative humidity in hypogeum environments

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Frasca, F.^1 ; Caratelli, A.^2 ; Siani, A.M.^3

Sapienza Universita di Roma, Department of Earth Sciences, P.le A. Moro 2, Rome

00185, Italy^1

Tecno.EL S.r.l., Electronic Technologies Company, via degli Olmetti 38, Formello, Italy^2

Sapienza Universita di Roma, Department of Physics, P.le A. Moro 2, Rome

00185, Italy^3

关键词: Capacitive effect;    Environmental conditions;    Field campaign;    Heating cycles;    Measurements of;    Vapor saturation;    Water vapour;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/364/1/012093/pdf
DOI  :  10.1088/1757-899X/364/1/012093

来源: IOP

【 摘 要 】

Hypogeum environments are characterized by high levels of relative humidity (RH). Most humidity sensors currently in use are based on the capacitive effect of the dielectric material to change according to water vapour uptake. In hypogeum environments the dielectric material can be saturated by water vapor, implying a significant error in the RH measurement. To improve the capacity of this type of humidity sensors, a modified hygrometer capacitive sensor, which uses a heating cycle to avoid the condensation, has been recently developed by Rotronic®. During four field campaigns in two different hypogea environments (the Monkey Tomb in Siena and the Mithreum of Caracalla Baths in Rome), RH was measured using the conventional capacitive sensor (CCS) and the heated capacitive sensor (HCS). The purpose of this study was to investigate the capability of HCS to detect RH variations when the environmental conditions were close to vapor saturation. Significant differences were found between the measurements of the two sensors: when RH was close to 100%, the CCS was not able to detect the RH decrease, giving only a measure of RH=100%, while HCS detected such a RH decrease. Therefore, these results encourage the use of HCS in the monitoring of RH levels in extreme humidity sites such as hypogea sites.