We normally use ASTM D664 for EHC TAN analyses. However, we need a portable method. Does anyone use ASTM D974 on Fyrquel fluid? Do you substitute any chemicals?

I do not run this but check with dexsil corp. they make 1 shot disposable test kits for TBN and TAN and perhaps this will corrolate with what you need they may even send you 1 for free to try out.
bruce

I have used the Dexsil Corp. TAN test kit's a couple of times. Very easy to use and when compared to results from a lab seemed to be accurate.