Our interest in determining accurate onset to second degree burn energy and its significance in computing the arc flash boundary is focused on the prevention of injury to the skin of a human who might be exposed to an arc-flash. 1967Įvaluation of onset to second degree burn energy in arc flash hazard analysis " A.Stoll, Heat Transfer in Biotechnology, Advances in Heat Transfer, v.4. Conversely, measurements of doses which produce the same damage over even a narrow range of intensities of radiation show that the "law of reciprocity" fails, for the doses are not equal. On the contrary, a very large amount of energy delivered over a greatly extended time produces no injury at all while the same "dose" delivered instantaneously may totally destroy the skin. Implicit in this treatment is the assumption that thermal injury is a function of dosage as in ionizing radiation, so that the process obeys the "law of reciprocity," i.e., that equal injury is produced by equal doses. Mathematically it is the product of the flux and exposure time for a shaped pulse. This quantity is defined as the total energy delivered in any given exposure required to produce some given endpoint such as a blister. A glaring example of this process is the "critical thermal load". "Serious misconceptions have crept into this field of research through adoption of rule-of-thumb terminology which has lost its identity as such and become accepted as fact.
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