I sincerely hope that one (or more) of you can answer this seemingly simple question.
Domestic heating oil is known variously as paraffin, kerosene and
28-second oil, and diesel fuel as 35-second oil. I have always assumed that the numbers 28 and 35 referred to some system of viscosity measurement, but which one? Google isn't terribly helpful, other than to tell me that there are more systems of measuring viscosity than I ever dreamt of!TIA
Pete