| 摘要 |
Method for detecting the freezing point of a hydrocarbon by placing a measured sample of the hydrocarbon in a container and placing a thermistor in the container into contact with the sample. The container is cooled until its temperature curve shows a noticeable plateau which is detected by the slope of the temperature curve which is being tracked by a first derivative circuit. The container is then insulated thus warming the sample and, as the last crystals in the sample melt, the slope of the curve momentarily accelerates causing the circuit to produce a voltage peak which is the freezing point of the sample.
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