- Fall 1998 "Update" Newsletter Article -
Temperature measurement systems tested
From CATI Publication
Copyright © 1998. All rights reserved.
study of temperature measurement systems has provided new clues for use in processing food products at Fresno State's microwave vacuum (MIVAC) technology laboratory.
Professor Matthew Yen recently completed trials comparing infrared and fiberoptic methods of measuring the temperature of food products as they are processed in the MIVAC unit. Details of the study are contained in a new CATI publication titled "Fiberoptics vs. Infrared - An Assessment of the Temperature Measurement in the MIVAC System." The document may be viewed through the Research Publications section of this web site.
Accurate product temperature measurement is critical to successful MIVAC processing, since high temperatures can damage tissues and cells, affecting the food's flavor and texture, Yen notes in his report. Infrared technology can effectively measure surface temperature of a food product during MIVAC processing, but tests using fiberoptic technology showed that the interior of the product rose up to 16 degrees hotter than the surface. This indicates that infrared may not provide the accuracy needed.
The drawback of fiberoptic is that it requires a sensor in the product and a cable run from the sensor to a control unit outside the MIVAC unit. This presents problems in maintaining an effective vacuum seal, Yen noted.
Yen concludes that IR temperature measurement must be "bench-marked" by the fiberoptic system to ensure accurate readings of both interior and surface temperatures.
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