Could you guys recommend a Proficiency Testing Program for used oil analysis. We used to be in the JOAP system, but went over to Conostan's, but suddenly Conostan stopped sending us samples (and they will not reply to emails...).

I know ASTM is starting something up soon, but is there any one else? BP?

ULMA (Utility lab mana***s association) has several oil round robins, I believe they have a used oil round robin. If you're business is utility based I'm sure they would include you in next year's program. Otherwise you may have to speak with them. Give me your email and I can forward the inforamtion