1. W. Ebenstein Duke University Barrel Pressure Drop Measurements  Purpose: u Measure pressure in module due to purging gas flow u Module could bulge if pressure too high  Method: u Module has 4 purging gas holes:  Use 2 for gas flow, 2 for pressure sensors u Measure pressure near input and output at 3 fixed flow rates of N 2  ~0.9 l/min, 3.5 l/min, 6.6 l/min

2. W. Ebenstein Duke University Barrel Pressure Drop Measurements  Duke setup:

3. W. Ebenstein Duke University Barrel Pressure Drop Measurements  Duke setup – detail of pressure sensor:

4. W. Ebenstein Duke University Barrel Pressure Drop Measurements  Results:

5. W. Ebenstein Duke University Barrel Pressure Drop Measurements  Interpolate to 1.5 liters/min N 2 : u (with CO2, pressures ~ 15% lower) u Type 3 module with nothing on output:  0.54 mbar near input  0.04 mbar near output u Effect of button attached to output:  +0.20 mbar near input  +0.22 mbar near output u Effect of gas fitting attached to output:  +0.24 mbar near input  +0.32 mbar near output

6. W. Ebenstein Duke University Barrel Pressure Drop Measurements  Example of stackup: