If “D61821” was a typo for another standard (like D618 for conditioning plastics, or D1821 for something else), let me know and I can help correct the number.
If you are a student or faculty member, your university library may have a site license to ASTM Compass. You can download the PDF for free through your institution's portal. astm d61821 pdf
: The sediment content is measured using a specified technique, typically involving filtration or a similar approach that allows for the quantification of sediment. If “D61821” was a typo for another standard