This formula is valid for the throughput of a compressible fluid (gas) thru a leak in a pressurized vessel. It is:
| Mass flow: |  |
| Volume flow: |  |
| Leak rate: |  |
With:
| Α: | Leak area |
| Ψ: | throughput function |
| pi: | pressure inside |
| ρi: | density inside |
| pa: | pressure outside |
| ρa: | density outside |
| R: | specific gas constant (air: 287, Helium: 2078 [J/(kg*K)]) |
| Τa: | Temperature outside |
Water bath leak testing at 1350mbar (19,6psi) pressure inside and 1043mbar (15,1psi) pressure outside (considering the hydraulic pressure of the water too):
| leak diameter in µm | leak rate in mbar·l/s |
| 1 | 1,4E-04 |
| 5 | 3,5E-03 |
| 10 | 1,4E-02 |
| 15 | 3,1E-02 |
| 20 | 5,5E-02 |
| 50 | 3,5E-01 |
| 100 | 1,4E+00 |
Machine Building Applications in Ultrasound Computer Aided Measuring Systems Electric and Acoustic Sensor Technology
