A semiconductor device includes a heavily doped first layer of a first conductivity type having a bulk portion and a mesa portion disposed above the bulk portion. In some embodiments, the methods and systems can include a viscosity in the ratio, determining a flow rate at ambient pressure using a factor based on a ratio of a gas pressure at the output and ambient pressure, andor, determining a flow rate at ambient temperature using a factor based on a ratio of a temperature at the output and ambient temperature. The method can be used for the investigation of the quality of peptides and proteins, particularly of pharmaceutical peptides and proteins.