Development of an Optical Fiber-Based Moisture Sensor for Building Envelopes.
Development of an Optical Fiber-Based Moisture Sensor
for Building Envelopes.
Healy, W. M.; Luo, S.; Evans, M.; Sucheta, A.; Liu, Y.
Ventilation, Humidity Control and Energy Proceedings.
Air Infiltration and Ventilation Centre (AIVC)
Conference and Building Environment and Thermal Envelope
Council (BETEC) Conference, 24th. Proceedings.
(International Energy Agency (IEA) Energy Conservation
in Buildings and Community Systems Program. Annex V:
Air Infiltration and Ventilation Centre.) October 14,
2003, Washington, DC, 277-282 pp, 2003.
fiber optic; humidity; moisture; sensors; temperature
Optical fiber-based moisture sensors have been developed
to help detect moisture problems in building envelopes.
The sensors are created with a coating on a long period
grating that is written onto optical fiber. As the
coating absorbs moisture from its surroundings, the
refractive index of the coating changes, thereby
changing the propagation of light down the fiber. In
addition to the humidity sensors, temperature sensors
based on Fiber Bragg Grating technology and Fabry-Perot
interferometry have been developed to provide
temperature compensation. Tests in a humidity chamber
show significant sensitivity of the sensors to humidity,
with a linear response to temperature. In addition to
tests in the environmental chamber, the sensors were
also tested as moisture content sensors on samples of
gypsum board, oriented strand borad and pine. These
tests again showed marked sensitivity to the moisture
level. The sensors are very appealing because of their
small size, durability, and ease of multiplexing and
could potentially serve as a vital tool in detecting
moisture issues in buildings.