Participating laboratories for their tests on sonic nozzles, with air or natural gas.
The participants must provide to the project manager their C^* calculation tools and information on the state equations used by their method (Johnson, Jacobsen, standard reference, etc.).
The C* calculations used by the laboratories will be compared using the same input reference conditions (see below). Other thermodynamic values (Z, C_p, C_v, p and V^*) calculated with state equations used in the C^* calculation method will be compared to reference documentation or equations.
Pressure: from 1 up to 80 bar,
Temperature: 0, 20 and 50°C,
Gas: dry air, ambient air and natural gas (Groningen, North Sea, Russia, etc.).
The same method for air and natural gas will then be used to re-calculate the results obtained from the sonic nozzle intercomparison EUROMET project N° 307) in order to improve the accuracy of the experimental discharge coefficient equation.
The results of this project will be used for the revision of ISO9300.