Originally Posted By: ironman_gq
Originally Posted By: Ducked
Originally Posted By: JHZR2
blotter test
Until I Googled it, I assumed that paper chromatography with solvent elution has been around since at least the end of the 19th century or earlier, but apparently it was very little known or developed before WW2.
This implies that even the blotter test would be quite innovative in the 20's, and the hero apparently isn't supposed to be a genius.
https://en.wikipedia.org/wiki/Oil_analysis
suggests that oil analysis is basically a post-war development (though tribology has a longer history).
This implies you might have to body-swerve historical accuracy and let him get a bit creative/ahead of his time.
IIRC water turbidity in rivers and lakes is measured by the depth at which a standard disk is obscured. If it works for hydrologists, such a method could be perhaps be adapted to measure the "blackness" of oil, without access to a means of actually measuring light, which might have been a challenging DIY project in the 20's.
The measuring range could be extended by diluting the sample with kerosene or virgin oil, and compared to "standard" suspensions of lamp black.
Blackness of oil might not be a very useful parameter, but perhaps your hero could combine it with sedimentation or magnetic separation to get more info.
Couldn't remember the name: Secchi Disk
http://water.epa.gov/type/rsl/monitoring/vms55.cfm
I think he's referring to the quick and dirty test for fuel dilution in the oil. Put a drop of oil on blotter paper and see if a fuel halo develops around the dark oil spot indicating excessive fuel in the oil.
Sure. But that's still paper chromatography, which apparently didn't exist as a concept before WW2.
It would have been practical for the OP's hero, but he'd have had to originate it, and he apparently isn't supposed to be a pioneer.
I've seen an approximate introduction date for the blotter test given somewhere, probably on the same machinerylubrication.com site Shannon cites above. Can't remember if it was 50's or 60's but certainly postwar. Don't have time to look for it now, but that site doesn't often give source citations anyway.