4 for the turbulent component of the flow proportionally to the square of the flow velocity or of the volume flow rate dv dt or 6 a a reduced differential pressure u03b4p or u03b4p rel results at high volume flow rates 6 a with the countersunk holes 41 and or 42 what is also achieved is that the turbulent flow component with a high reynolds number is reduced at high flow rates advantageously to further improve the laminarity of the volume flow 6 a a ratio of the total length l to the total diameter d 0 of the differential pressure means 4 is selected to be greater than 1 preferably 1 3 and by particular preference 1 5 thus the formation of laminar pipe friction in each flow duct 40 is improved and the relative proportion of turbulent flow is forced back the larger the factor total length to total diameter l d 0 is the more linear is the correlation between the volume flow rate 6 a through the gas pipe 6 a and the differential pressure u03b4p p 1 u2212 p 2 generated by the differential pressure means 4 which pressure is in turn proportional to the volume flow rate 6 b through the bypass 3 and the gas meter 2 or its thermal flow sensor preferably the flow ducts 40.