Abstract
The open capillary melting point has been adopted as a characteristic value of fats and waxes in some standards of testing materials such as A.O.C.S. Official Methods, JIS and J.P.
In these standards some disagreements are found concerning the practical procedures of measurement and the sort of materials applicable. The authors studied the procedures and its applicability from the stand point of repeatability of the measurement. The materials used were hydrogenated tallow, hydrogenated castor oil, mink fat, cetanol, hydrogenated spermaceti, bees wax, candelilla wax, bleached montan wax, paraffin wax and ceresin. The repeatability has been determined from five replicated measurements with five capillaries and expressed as standard deviation.
Under carefully controlled measuring conditions, it was observed that the repeatability depends primarily upon complexity of the chemical nature of the samples. It is quite conceivable that the open capillary melting point is applicable to rather limited sorts of materials when the repeatability of the measurement must be in the range of ±1°C.
