Arb. Units

I frequently run into 'arb. units' when working with blood coagulation rates. However, I have not been able to find an explanation of what these units refer to, how they are calculated, and whether they have conversion equivalencies. Does anyone here know anything about arb. units or have a reference I can use to learn about them?

Thanks.

I found an arb front bumper here locally used. The guy doesnt know what it fits??? My question to you, is there any way to find out what it will fitpart # or stamping on the bumper itself?? Any help would be appreciated.

Arbitrary unit means that you cannot calibrate your data or compare to other data. "Arbitrary" means you produced it.

In other words, if you walk in the mountains, and you measure your distance with a stick, then, as a scientist, you'd write "the distance was 5000 au", without any information about the length of your stick.

Or a more serious example: imagine you're looking at a cell through a microscope, and would like to say how big the cell is, but you don't have a scale in milimeters. Then you could put a small object, let's call it a "red ball" next to the cell, and when you say "my cell was two red balls wide", then you're using your arbitrary unit of "red ball".

Since i am working in the field of non-linear optics, i have found the use of arb. units for 'Intensity', 'Conversion Efficiency' in a no. of journals.