## rate of change ratio

https://doi.org/10.1351/goldbook.R05145
The quotient of two rates where the quantities are of the same kind in the same system for different components: $\frac{\text{d}Q_{1}/\text{d}t}{\text{d}Q_{2}/\text{d}t}$ For finite time intervals, mean rate of change ratio is: $\frac{\Delta Q_{1}/\Delta t}{\Delta Q_{2}/\Delta t}=\frac{\Delta Q_{1}}{\Delta Q_{2}}\ \Delta t$ Rate of change ratio has the dimension one. The denominator is often called the reference quantity. Examples are: mass rate ratio, $$\frac{\text{d}m_{1}/\text{d}t}{\text{d}m_{2}/\text{d}t}$$; @[email protected] rate ratio, $$\frac{\text{d}n_{1}/\text{d}t}{\text{d}n_{2}/\text{d}t}$$.
Source:
PAC, 1992, 64, 1569. (Quantities and units for metabolic processes as a function of time (IUPAC Recommendations 1992)) on page 1572 [Terms] [Paper]