Testing and development of plastic optical fiber as humidity and temperature sensor

Abstract

This experiment has developed and tested a plastic fiber optic-based temperature and humidity sensor (FOTHS). In the FOTHS test, the leading equipment is needed, such as a single model plastic optical fiber, a test chamber, a time-domain reflectometer (OTDR), a computer for data acquisition, and silicone oil used as a substitute for the 3 cm long optical fiber cladding layer. Silicone oil is used as a sensor material because it has a high sensitivity to changes in temperature and humidity. Optical fiber testing is carried out in a light-tight test chamber by changing the temperature and humidity. Changes in light intensity with changes in temperature and humidity are measured by OTDR, with information in voltage changes. At a constant temperature and variable humidity, information was obtained that the light intensity increased linearly at 45 °C with an increase in voltage of 0.0057 volt/1% RH. At constant humidity and variable temperature, information was obtained that the light intensity will decrease linearly at 20% RH with a voltage drop of 0.0171 volt/1 °C. Changes in voltage to variations in temperature and moisture make plastic optical fiber a temperature and humidity sensor.