refractometer-project-symbol question!

[NoobieNemo]

we are using a refractometer at school for a project and we need to find out what do the two little oo mean? Like in the booklet that came with the refractometer, it says 0-100%o...there are two little oo's under the / sign,,what do they mean?

thanks

[huggett]

I think it means parts per thousand....

% = parts per 100
%o = parts per thousand

A refractometer measures in parts per thousand, so I'm sure thats what the symbol means.