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A Kofler bench, or Kofler heating bar; Kofler hot bar; Kofler hot bench, in German, Kofler-Heizbank, [1] is a metal strip with a temperature gradient (range room temperature to 300°C). Any substance can be placed on a section of the strip revealing its thermal behaviour at the temperature at that point. [ 2 ]
During heating, the point at which melting is observed and the temperature constant is the melting point of the sample. [1] A more modern method uses dedicated equipment, known as a melting point apparatus. A slow heating rate at the melting point is needed in order to get an accurate measurement.
For example, the melting point of silicon at ambient pressure (0.1 MPa) is 1415 °C, but at pressures in excess of 10 GPa it decreases to 1000 °C. [13] Melting points are often used to characterize organic and inorganic compounds and to ascertain their purity. The melting point of a pure substance is always higher and has a smaller range than ...
For pure elements or compounds, e.g. pure copper, pure water, etc. the liquidus and solidus are at the same temperature, and the term melting point may be used. There are also some mixtures which melt at a particular temperature, known as congruent melting. One example is eutectic mixture. In a eutectic system, there is particular mixing ratio ...
Thermogravimetric Analysis (TGA) may be more useful for decomposition behavior determination. Impurities in polymers can be determined by examining thermograms for anomalous peaks, and plasticisers can be detected at their characteristic boiling points. In addition, examination of minor events in first heat thermal analysis data can be useful ...
While the outward designs of apparatuses can vary greatly, most apparatuses use a sample loaded into a sealed capillary tube (melting-point tube), which is then placed in the apparatus. 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 ...
The Joback method, often named Joback–Reid method, predicts eleven important and commonly used pure component thermodynamic properties from molecular structure only. It is named after Kevin G. Joback in 1984 [1] and developed it further with Robert C. Reid. [2] The Joback method is an extension of the Lydersen method [3] and uses very similar groups, formulas, and parameters for the three ...
This point may be accurately determined by pressing the thermometer into melting snow. 0,1,2: the heats of air in winter 2,3,4: the heats of air in spring and autumn 4,5,6: the heat of air in summer 6: the heat at midday about the month of July 12: 1: the greatest heat which a thermometer takes up when in contact with the human body 14: 1 + 1 ⁄ 4