This ballot is to include D7668 as an additional test method in the Cetane Number section as a method for measuring DCN which can be compared to the cetane number specification of 40. D613 is maintained as the referee method. A large interlaboratory study was conducted in 2013. In this study D7668 tested 20 samples of both #1 and #2 Diesel, B5 and B20 Biodiesel Blends and Biodiesel. The precision obtained was R=0.88 for a DCN of 40 compared to R=2.8 for D613. No bias was observed for these samples when statistically compared to the same samples tested by D613. The research report RR:D02-1771 supporting the precision statement can be obtained from the technical contact.
Keywordsbiodiesel; biodiesel blend; diesel; fuel oil; petroleum and petroleum products;