Table C5. Pressure loss and air flows through Bosch vacuum Cleaner 9/14/2007 Round 2

Before (B) or after (A) adding 5 pounds

Total weight of debris transferred (lb)

Venturi meter δP (inches of water)

Static Pressure Measurements with manometer (inches of water)¹

Absolute pressures measured with pressure transducers (psi)

Time loading

Time to stop loading

Air flow (from venturi meter) (cfm)

in bag

after bag

δP bag

between bag & filters (55481)

after final filters (53748)

B

5

10.8

-1.4

-4.3

 2.9

 13.874

13.539

11:40am

11:41am

86.24

A

5.2

-0.6

-31.4

30.8

13.015

12.787

60.05

B

5

6.6

-1.5

-25.8

24.3

13.201

12.963

11:49am

11:49am

67.64

A

 3.3

-0.4

-31.2

30.8

12.67

12.495

47.75

B

5

6.5

-0.8

-26.8

26

13.175

12.904

11:56am

11:57am

67.13

A

2.5

-0.3

-45.9

45.6

12.527

12.344

41.46

B

5

3.6

-0.5

-40.5

40

12.704

12.545

12:03am

12:04am

49.90

A

2

-0.2

-48.7

48.5

12.426

12.278

37.00

B

5

2.9

-0.4

-42.9

42.5

12.628

12.461

12:10am

12:11am

44.71

A

1.6

-0.2

-51.5

51.3

12.325

12.194

33.00

B

5

2.2

-0.3

-47.5

47.2

12.476

12.328

12:18am

12:20am

38.84

A

1.2

-0.1

-54

53.9

12.241

12.127

28.48

B

5.4

4.7

-0.5

-33.5

33

13.268

12.746

12:27am

12:28am

57.08

A

1.6

-0.2

-51.3

51.1

12.325

12.211

33.00

Final

3.1

-0.4

-41.4

41

12.687

12.503

12:34am

46.25

¹ Static pressure is the difference in pressure from atmospheric pressure. Negative static pressure indicates that pressure is less than atmospheric pressure.