RULER help

1- Volume of oil used in test matches the RULER setting?

2- If using 200, try 400.

3- should be 1, - Ask Jeff Chapin for help.

I've been using 400 uml and the green solvent. I have the settings right according to the manuel.

We use that test in my lab as well. Can you post an image or two as well as your procedure?

I have noticed that waiting for the sand to settle after vigorous shaking (usually 10 seconds of shaking to 30 seconds of waiting) helps with peak strength. Also testing the same sample multiple time in a row (reagitating in-between tests) can help.

What new oil are you analyzing as 100% standard? What color solvent are you using? The fact that the peaks are "almost unnoticable" sounds like something isn't right - antioxidant level is very low, oil getting on electrode surface (droplet on top of solvent after preparation?), etc. The fact that you are expecting valleys, does oil have two types of antioxidants present?

I'm testing cheveron gst 32. The new sample that I'm using as standard was taken last year but has been sealed since then. I'll try to get some pictures up but we were having trouble with our IT getting the software on our computers. The graph has one large peak but it's hard to tell where the specific points are of each valley.

My procedure is as follows:
I clean the electrode with an alcohol pad, dry it with a lent free tissue, and set it in an empty vial to the side. Then I open the container of new oil and take some of it into the pipette that was included and empty it elsewhere first to make sure there are no contaminants introduced. Then I put the 400 uml into the green vial and shake for about 15 secs, then let it settle for 4-5 minutes. Finally I put the electrode in the sample vial and screw it on before pushing the "run" button.

I haven't tried running the same sample more than once, maybe I'll give that a shot. Also I have noticed some beads of oil of the surface of the solvent - is there any way to get around that without touching the electrode to it?

Are you running green solution with the main peak at around 9-11 or 13-15 seconds? Draw the baseline from the flat region before the peak starts and to a point on the curve after the peak has come back down and leveled off - will not be a valley unless a second peak starting . Main thing is the line should not cross the curve line.
Easy way to get peak to show here - do a screen save and paste RULER spectrum into Word for attachment.
To negate the drop on the surface, after shaking let sand settle for 10 seconds and insert electrode. Let sit for another 30 seconds then analyze. The oil droplet will agglomerate on the sides of the electrode. Pull the electrode out, wipe down the sides with a Kimwipe. Then do a repeat analysis - shouldn't matter if you reshake or not unless not all of the antioxidant got extracted into the solvent/oil basestock coated sand during the first shaking. Make sure you screw the vial onto the electrode (electrode doesn't rotate). Doesn't need to be tight just want the electrode to be vertical/stable during test

phobos, is there any chance we could connect on Monday? I am sure I can walk you through your issue without a problem.

j.chapin@fluitec.com