FAQ-L.5: What does the leakage rate unit mbar l/s mean and how can it be converted into other units?

If, in a volume of 1 liter, the gas pressure drops by 1 mbar within 1 s, this corresponds to a leakage rate (outflow of gas) of 1 mbar l/s. The unit mbar l/s is relatively difficult to imagine, but is typically used alongside units such as Pa m m³/s, Torr l/s or atm cc/s in the vacuum applications.

The indication becomes more understandable if the loss quantity is indicated in other units. For example, units such as g/a or oz/y are used in air conditioning technology. For the indication of leakage losses in compressed air systems, the unit l/min has prevailed.

Examples of unit conversion (at Δp = 1,013.25 mbar, 273.15K or 0°C, medium air):


10⁰ mbar l/s

≙ 1 mbar l/s
≙ 10⁻¹ Pa m³/s
≙ 1 cm³/s (≙ 1 cm³ of air flows through a leak in 1 second)

10⁻² mbar l/s≙ 0,01 mbar l/s
≙ 10⁻³ Pa m³/s
≙ 6*10⁻¹ ml/min ≙ 6*10⁻⁴ l/min
≙ 4,3*10⁻⁵ kg/h ≙ 3,75*10⁺² g/a

Contact Us!

We will be happy to help you.

For more information regarding applications and pricing, please feel free to contact us.

Receiver: bkavanagh@sonotecusa.com

Do you have any questions?

Feel free to contact us! We will be happy to help you.