Dew Point and Relative-Humidity Smart Measuring System

• Published in: IEEE transactions on instrumentation and measurement Vol. 55; no. 6; pp. 2259 - 2264
• Main Authors: Postolache, O., Silva Girao, P.M.B.S., Pereira, J.M.D., Ramos, H.G.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-12-2006; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Bifurcation; Calibration; Channels; Chilled; Computer programs; Cooling; Design engineering; Dew point; dew-point (DP) measurement; Diode lasers; Instrumentation; intelligent control; Laboratories; Mirrors; Narrowband; optical detection; Optical detectors; Optical pumping; Optical sensors; Particle measurements; relative humidity (RH); Software; virtual instrumentation
• ISSN: 0018-9456; 1557-9662
• DOI: 10.1109/TIM.2006.884132

In this paper, a new design and implementation of an air dew-point smart measuring system are presented. The system also implements a relative-humidity sensing structure, based on dew point (DP) and ambient-temperature measuring channels acquired data, and its design suits particularly laboratory applications. The DP is detected on the surface of a chilled mirror using an optical system. The main elements of the measuring system are a bifurcated-fiber bundle, a laser diode, and a narrowband optical detector. Mirror cooling is made using a current-mode-powered Peltier heat pump. The current control is performed using a digital controller implemented using a data-acquisition board programmed with LabVIEW software