Indicates the pressure drop across the column (in bar) at the given flow rate, eluent viscosity, and column geometry.
The pressure drop across the column is calculated from the Darcy equation. See Bird, R. B.; Stewart, W. E.; Lightfoot, E. N. Transport Phenomena; Wiley & Sons: New York, 1960.
where
ΔP = pressure drop across column (bar)
η = eluent viscosity (cP)
ν = flow velocity (cm/s)
L = column length (mm)
dp = particle size (μm)
For the purpose of this simulator, the pressure drop across the column is considered to be the only significant contributor to the backpressure. When adjusting the chromatographic conditions, be sure to check that the backpressure is within a reasonable range. Most HPLC instruments can reach a maximum pressure of 400 bar, while most UPLC instruments can reach a maximum pressure of 1000 bar.