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A Microwave Oven with Variable Continuous Power and a Feedback Temperature Controller
Author(s) -
Tong C. H.,
Lentz R. R.,
Lund D. B.
Publication year - 1993
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1021/bp00023a600
Subject(s) - microwave oven , microwave , controller (irrigation) , materials science , intensity (physics) , microwave cavity , microwave power , power (physics) , temperature control , optical fiber , analytical chemistry (journal) , temperature measurement , acoustics , electrical engineering , environmental science , optics , chemistry , computer science , mechanical engineering , physics , telecommunications , chromatography , thermodynamics , engineering , agronomy , biology
The power supply circuit of a domestic microwave oven was modified so that the field intensity in the cavity could be changed continuously. The oven was further fitted with a feedback temperature controller for controlling product temperatures during microwave heating by cycling the magnetron on and off. The temperature controller consists of a fiber optic temperature sensing system, a computer, an optocoupler, and a mechanical relay. White bread, moist sponges, and a 5‐mL water load were used to test the performance of the oven. The temperature control capability was greatly influenced by the field intensity of the cavity and less influenced by the data acquisition rate. Experimental data indicated that it was possible to maintain the sample temperature within ±0.3°C at 60°C and within ±0.6 °C at 80°C when a proper power level was used.