Table C3. Pressure loss and air flows through Bosch vacuum Cleaner 9/14/2007 Round 1

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

11.5

-1.1

-2.2

1.1

13.95

13.631

9:12am

9:14am

88.92

A

3.5

-0.5

-40

39.5

12.695

12.545

49.19

B

5

8.6

 -0.9

-18.8

17.9

13.436

13.147

9:26am

9:28am

77.11

A

2.3

-0.7

-46.6

45.9

12.476

12.361

39.73

B

5

3.9

 -0.4

-38.2

37.8

12.796

12.603

9:37am

9:39am

51.96

A

1.9

-0.3

-49.5

49.2

12.392

12.244

36.04

B

5

5.4

 -0.6

-29.8

29.2

13.049

12.821

9:49am

9:50am

61.20

A

2.6

-0.3

-45

44.7

12.535

12.403

42.30

B

5

3.1

 -0.3

-42.3

42

12.628

12.461

9:58am

9:59am

46.25

A

1.9

-0.2

-48.9

48.7

12.409

12.269

36.04

B

5

2.3

 -0.4

-47.1

46.7

12.493

12.328

10:10am

10:12am

39.73

A

1.3

-0.2

-53.8

53.6

12.224

12.136

29.67

B

5

1.9

 -0.2

-49.9

49.7

12.359

12.253

10:26am

10:28am

36.04

A

1.1

-0.1

-56.4

56.3

12.157

12.077

27.24

Final

1.5

-0.2

-52.9

52.7

12.283

12.169

10:35am

31.93

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