Sonic nozzles (7 pieces) with nominal flow rates 2 L/h, 16 L/h, 60 L/h, 250 L/h, 600 L/h, 1600 L/h, 2500 L/h will be used to compare primary low-pressure test facilities.
The laboratories should carry out the calibration using their common procedures.
The procedure described in PTB Testing Instruction Volume 25: Gas meters – Test rigs with critical nozzles is recommended to be used.
The parameters QV,20,tr,1000[L/h] and cpE[-] are required to be determined for each sonic nozzle.
Each laboratory will be responsible for the transfer of the sonic nozzles to the next laboratory.
No other costs are expected.
- Test gas: air
- Upstream sonic nozzle pressure: near atmospheric
- Test temperature: (19.5 ÷ 22.5) °C