- Method ASTM D473
- Repeatability 0.017 + 0.255(S)
- Reproducibility 0.033 + 0.255(S)
- Blending linear
- Additive Correction No
This test method covers the determination of sediment in crude oils and fuel oils by extraction with toluene. The precision applies to a range of sediment levels from 0.01 to 0.40 % mass, although higher levels may be determined.
This method is performed by first filling a porous ceramic thimble with the sample to be analyzed. The weight of both the thimble empty and the amount of sample must be taken. Next the thimble is placed into a wire basket hanging from a condenser inside a beaker full of toluene. The toluene is then boiled and the vapors collect on the condenser and drip back into the thimble. This clean toluene removes all of the soluble oils and leaves only the sediment behind. Once the toluene drips clear the thimble is pulled, dried, and then cooled for a final weight. The added weight in the thimble is then calculated as a percentage of sediment in the sample.
This method is very important to the industry because volumes bought and sold are adjusted basis water and sediment results. It is also important to refiners as the sediment will collect in the bottom of the distillation towers and cause issues with product quality.