Design
While the outward designs of apparatuses can vary greatly most apparatuses use a sample loaded into a sealed capillary (melting point capillary) that is then placed in the apparatuses. The sample is then heated, either by a heating block or an oil bath, and as the temperature increases the sample is observed to determine when the phase change from solid to liquid occurs. The operator or the machine records the temperature range starting with the initial phase change temperature and ending with the completed phase change temperature. The temperature range that is determined can then be averaged to gain the melting point of the sample being examined.
Apparatuses usually have a control panel that allows the starting and final temperatures, as well as the temperature gradient (in units per minute) to be programmed. Some machines have several channels which permit more than one sample to be tested at a time. The control panel might have buttons which allow the start and end of the melting point range to be recorded.
Read more about this topic: Melting Point Apparatus
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