Atmospheric equivalent initial boiling point

With very heavy crude oil or viscous products, a preferred alternate distillation method (ASTM D-5236) should be used (instead of ASTM D-2892) for heavy crude oil above a 400°C (752°F) cut point. In the spinning band method (Fig. 10.3), fractions of feedstocks such as residual fuel oil with an initial boiling point above room temperature at atmospheric pressure can be investigated. For such materials, the initial boiling point of the sample should exceed room temperature at atmospheric pressure. The distillation is terminated at an atmospheric equivalent temperature of 524°C (975°F) and a pot temperature of 360°C (680°F). 

The sample is distilled at an accurately controlled pressure between 0.13 and 6.7 kPa (1 and 50 mm Hg) under conditions that are designed to provide approximately one theoretical plate fractionation. Data are obtained from which the initial boiling point, the final boiling point, and a distillation curve relating volume percent distilled and atmospheric equivalent boiling point temperature can be prepared. 

A9.6.9 The apparatus will automatically record the initial boiling point, find boiling point, percent volumes recovered with corresponding actual temperatures, and distillation rates. Actual temperatures recorded are automatically converted to Atmospheric Equivalent Temperatures (AET) using software supplied by the manufacturer. This conversion should be based on (A7.1). 

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