The New Jersey Institute of Technology's
Electronic Theses & Dissertations Project

Title:	An embedded controller-based fiber optic sensor for use in fresh concrete
Author:	Zhang, Zhaowu
View Online:	njit-etd1992-123 (xii, 127 pages ~ 3.1 MB pdf)
Department:	Department of Electrical and Computer Engineering
Degree:	Master of Science
Program:	Electrical Engineering
Document Type:	Thesis
Advisory Committee:	Ansari, Farhad (Committee chair) Rosenstark, Sol (Committee member) Niver, Edip (Committee member)
Date:	1992-05
Keywords:	Concrete -- Air content -- Measurement -- Data processing Concrete -- Air content -- Measurement -- Instruments Fiber optics -- Industrial applications
Availability:	Unrestricted
Abstract:	The principle of refraction and reflection of light in optical fibers is applied to detection of air bubbles in a previous thesis. In the earlier work, a microcomputer was employed in acquisition and processing of air bubble data. In the present thesis, an embedded controller system is interfaced and programmed in order to replace the microcomputer. In this way, the system can be more easily integrated into field construction operations. Reflected light intensity signals are detected and analyzed by a microcontroller. The entrained percentage of air in concrete is displayed immediately. The signal can be transferred through a UART (Universal Asynchronous Receiver Transmitter) to a master IBM compatible personal computer. Analysis of reflected light intensity produces a graphic measurement of the air content of fresh concrete. Accuracy of the system is evaluated through extensive laboratory and field trials.