Active Standard ASTM D7821 | Developed by Subcommittee: D15.25
Book of Standards Volume: 15.05
1.1 This test method covers a technique for field testing the concentration of aqueous urea-based diesel exhaust fluid (DEF) prescribed for use in diesel engines equipped with selective catalytic reduction technology and is not intended to circumvent or replace the more accurate determination of urea content by refractive index laboratory method, described in ISO 22241-2, Annex C.
1.2 This test method is designed solely as a quantitative test to determine the concentration of urea in DEF and does not purport to determine the quality of DEF nor to detect trace or other contaminants therein. Biuret content of DEF creates a known bias in this test method. See section 9.2.1 for details.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
ISO StandardISO22241 22241Diesel engines--NOx reduction agent AUS 32
ICS Number Code 75.160.20 (Liquid fuels)