A new type of dynamic optical dew-point sensor using a laser diode and an optical fiber cable

Author

Matsumoto, Shigeaki

Author_Institution

Dept. of Inf. Syst. Eng., Ind. Technol. Univ., Sagamihara

fYear

2005

fDate

Oct. 30 2005-Nov. 3 2005

Abstract

A new type of optical dew-point sensor using a laser diode and an optical fiber cable has been devised. The measurement motion of the sensor is based on the control of quantity of dew deposited on a gold plate with rough surface oscillatory at low level with time by using a proportional control circuit with an integrator. The intensity of scattered light from the surface of the plate is inversely proportional to the quantity of dew deposited on the surface so that the dew points could be determined dynamically at the maximum and minimum points of the intensity of scattered laser light at which dew begins to deposit and also to disappear. Dew points ranged from -3degC to 40degC were measured in the atmosphere from 10degC to 50degC with an accuracy of plusmn0.5 degC that was plusmn2%RH with the time interval of measurement from 31sec to 6sec

Keywords

fibre optic sensors; humidity sensors; measurement by laser beam; -3 to 40 C; 10 to 50 C; 6 to 31 sec; dew-point sensor; dynamic sensor; laser diodes; laser light intensity; measurement motion; optical fiber cable; optical sensor; proportional control circuit; rough surface oscillatory; Diode lasers; Light scattering; Optical fiber cables; Optical fiber sensors; Optical scattering; Optical sensors; Proportional control; Rough surfaces; Surface roughness; Time measurement;

fLanguage

English

Publisher

ieee

Conference_Titel

Sensors, 2005 IEEE

Conference_Location

Irvine, CA

Print_ISBN

0-7803-9056-3

Type

conf

DOI

10.1109/ICSENS.2005.1597894

Filename

1597894