title: Humidity and pressure sensor based on internal reflection.
abstract: A low-cost humidity and pressure optical sensor, based on the internal reflection phenomenon, is presented. It takes advantage of the phase difference acquired by s- and p-polarized light undergoing internal reflection to generate an easily detectable minimum in the reflected profile, in a position corresponding to the critical angle. The apparatus presents good sensitivity to relative humidity changes above 70% and a response time below one second. The same device is also capable of measuring changes in pressure and can be used as a vacuum gauge between 1 and 1000 mbar.
authors.forename: J F M
authors.initials: JF
authors.lastname: Domenegueti
authors.forename: S C
authors.initials: SC
authors.lastname: Zilio
mesh_terms: D004784:Environmental Monitoring / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006813:Humidity; D008365:Manometry / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation*; D020349:Surface Plasmon Resonance / Q000295:instrumentation*; D018511:Systems Integration; D014160:Transducers, Pressure; D014867:Water / Q000032:analysis*
chemical_list: D014867:Water