The volumetric flow rate (V) is the measure of a volume of fluid (gas) passing a point in a system per a unit of time. The volumetric flow rate can be calculated as the cross sectional area (A) for flow and the average flow velocity (v). Stated mathematically as:
V=Av
In terms of a round cylinder the flow rate is:
V=Pr2v if we substitute v=d/t
V=Pr2d/t V= (area) x (distance)/(time)
This is the basic equation used in calculating the volumetric flow rate for all DryCal units.
Note: Some of the units used for volumetric flow include L/m, ccm, m3h, cfm, and cfh.
The standardized flow rate (Vs) is the volumetric flow rate corrected for both pressure and temperature. When using the standardized flow rate, the reference pressure and temperature are usually fixed at standard conditions. These conditions are usually defined as 1 atm (760 mmHg) for pressure and 273°K (0°C) for temperature. These corrections are based on the ideal gas law. The relationship of standardized flow rate (Vs) to the volumetric flow rate (V) is:
Vs=V*(P1/760)*(273/T1)
Where: Vs = the standardized flow rate at 760 mmHg and 0°C (273°K)
V = the volumetric flow rate
T1 = the absolute temperature of V (K)
P1 = the atmospheric pressure of V (mmHg)
Note: Sometime the reference temperature may be something other than 0°C.
Note: Some of the units used for standardized flow include sL/m, sccm, sfm, and scfh.