Sonic Nozzles are also known as “Critical Flow Venturis” or “Critical Flow Nozzles
Below are descriptions of typical sonic nozzle configurations and ranges for both mass and volume flow gas applications.
Manual (Sonic Nozzles & Flow Computer)
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Operator Adjusts Flow and Reads Flow ComputerOperator Instruments and Reads Unit Under Test
If Po varies 4:1, then ṁ or volumetric flow Unit Under Test varies 4:1 for each sonic nozzle Air or N2 @ Ambient Temp., 2.7 slpm, 0.10 scfm, 0.06 g/s, 1.3E-4 lbm/s minimum |
Semi-Automated (Mass or Volume Flow Controller)
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Operator Inputs Desired Flow which is set Automatically and Reads Flow ComputerOperator Instruments and Reads Unit Under Test
Air or N2 @ Ambient Temp., 2.7 slpm, 0.10 scfm, 0.06 g/s, 1.3E-4 lbm/s minimum
Where K can vary 26 = 64: 1 If Po is constant, then volumetric flow Unit Under Test will range 64:1 If Po varies 4:1, then ṁ will range 4 * 64 = 256:1 |
Fully-Automated (Gas Flow Calibrator)
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System contains Pressure & TemperatureInstruments for, and Reads/Accepts Output from Unit Under Test
Where K can vary 213 = 8192: 1 Air or N2 @ Ambient Temp., 2.7 slpm, 0.10 scfm, 0.06 g/s, 1.3E-4 lbm/s minimum If Po varies 4:1, then ṁ will range 4 * 8192 = 32768:1 If Po is constant, then volumetric flow Unit Under Test will range 8192:1 |
GFC: Bios Option (Gas Flow Calibrator)
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ṁ or volumetric flow Unit Under Test can range 10000:1Air or N2 at Ambient Temperature 5 sccm, 1.7E-4 scfm, 1.E-4 g/s, 2.4E – 7 lbm/s minimum |