Abstract: Most automatic distillation range testers for petroleum products operate in a batch mode, which requires repeated manual intervention and is highly susceptible to subjective factors. Such operational limitations often result in inaccuracies in volume measurement, volume deviations arising from temperature fluctuations before and after sample distillation, contamination of the recovered liquid with condensed water, and increased material loss. To mitigate these issues, an automated continuous distillation range determination system for petroleum products was designed and developed. This system integrates key functionalities including automatic continuous sample injection, automated distillation, real-time automatic measurement of recovered volume and residual volume, as well as automated cleaning and drying processes for distillation range determination. Additionally, it calculates the distillation data of samples through atmospheric pressure correction.This system effectively addresses the inherent drawbacks of traditional distillation range testing—such as inaccurate sample metering, sample volatilization during transfer, volume deviations caused by temperature variations before and after distillation, and the inability to perform continuous testing. The system significantly reduces manual operation costs, while reducing the consumption of cleaning agents and testing time by one-third. Comparative analysis between this system and the automated method specified in the current GB/T 6536 standard demonstrates that the slope of the linear function curve of the trend line is close to 1, with a coefficient of determination exceeding 0.999, indicating substantial consistency between the test results. Furthermore, the temperature differences at each comparison point comply with the repeatability requirements of the automated method in the GB/T 6536 standard, and the repeatability of the test results obtained by this system outperforms that of the automated method specified in GB/T 6536.

Key words: petroleum products, automatic, continuous, distillation range determination