Soot Conversion

[Tsoloist]

Just wondering what the process or calculation steps are for converting soot as a Wt % into a UFM number as given by CAT analysis.
For example the FTIR machine returns a value of 1.55 Wt % soot, what would the corresponding UFM be?

 

[JHZR2]

UFM is what? Wt% is a pretty straightforward figure.

 

[Rand]

I'm guessing PPM, but no idea about what UFM stands for.

 

[JHZR2]

I found this here.

Originally Posted By: Meathead
From the CAT lab:

"...the numbers you see are not particles per milliliter (that is for particle counts only), they are "UFM" or "Unsubtracted FTIR Method" numbers. These are based on absorbance of infra-red light at different wavelengths. You can convert the soot UFM number to percent weight using the attached chart. Simply look up the number on your report in the "Abs" column on the chart, ignoring the decimals, and to the right you will find the corresponding percent weight result. For example, your most recent soot UFM result was 37, so you would find the Abs line for 0.37, which tells you that your percent by weight is 0.56%. This chart only works for the soot number."

I'm not sure how (on this forum) to copy and post the chart he attached to this email, so I hope this explanation is sufficient.

Given his conclusion that the Soot reading for my UOA is 56%, please also tell me your thoughts about that.

 

[Tsoloist]

UFM stands for Unsubtracted FTIR Method, I don't know the units for it sorry, I just get used oil samples back with a UFM reading instead of a weight percentage (%) reading and I was wondering how to convert the two?

 

[Tsoloist]

Yeh the "attached chart" is what I am looking for haha
Thanks