The Volume class correctly has 1 **barrel** = 42 **US gallons**.

The Volume Flow Rate class has a simple reference for 1 **US gal/day** equals 1440 **US gal/min**. However, the canonical value of 0.090849882816 **m3/s** doesn't seem right. If you divide that number by the **barrel per day** canonical value, you do not get 42 as you would expect. It looks like the canonical value for **US gal/min** was mulitplied by 1440 instead of being divided by 1440.

I'm thinking if the math is to be correct that the canonical value for **US gal/day** should be along the line of 4.38126E-08 m3/s.

And then the bigger question becomes ... does such inverted numbers occur elsewhere when one UOM is based on another simple non-canonical reference?

I got two points about the calculations you made:

1) 1 US gal/day should be equal to 1/1440 US gal/min. When we make the time smaller (day to minute) we should have a smaller amount of mass in order to end up having the same flow. In my mind this one is the incorrect one.

2) By the same token 1440 US gal/min is in fact equal to 0.090849882816 m3/s. Because 1440 US gal = 5.45 m3. Therefore to get the same flow per second, we need to divide this number by 60: 5.45/60=0.0908.