Comments on copper plate temperature monitoring are: * Some people use this type of temperature monitoring to start the day as an element of an oven capability measurement and monitoring program. * Using a copper or other metal plate, like aluminum, or a plain piece of FR-4 eliminates interaction from the substrate design and fabrication during the temperature measurement. * Measure temperature what�s important to your process. Dunno, rail-to-rail, front-to-back, and center of the plate / board? * Plate / board is maybe a foot long, but would length could vary depending on the width [of the oven] so there wasn�t too much sag during reflow. * Measure something important like a variant of time over liquidous or variation center to side. * Accuracy is as good as your �profiler / thermocouple�. * Maintenance of the 'plate / thermocouple' assembly is important, of course.
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