NOISE AND VIBRATION CONTROL Episode 9 pot

... middle-, and high-frequency noise; and noise control materials and treatments vary in their effectiveness as a function of frequency (usually, low frequency noise is more difficult to control; most ... 5-805-4/AFJMAN 32-1 090 CHAPTER 10 NOISE AND VIBRATION MEASUREMENTS 10-1. Objective. In the event that demonstration of compliance with noise or vibration criteria is...

Ngày tải lên: 13/08/2014, 05:22

... of the fan (b. (1) above) by octave bands. These steps are shown below. Octave Band Center Frequencies 63 125 250 500 1k 2k 4k Total Fan Lw 104 100 96 95 91 89 85 (b.(1) above) Total Duct IL 44 ... Mounting for Fan and Drive-Assembly of Propeller-Type Cooling Tower. 8-6 TM 5-805-4/AFJMAN 32-1 090 CHAPTER 8 VIBRATION CONTROL 8-1. Introduction. This chapter provides the details of v...

Ngày tải lên: 13/08/2014, 05:22

... Capacity 500 (Hz) 500 Tons Tons or More 31 92 92 63 93 93 125 94 94 250 95 95 500 91 93 1000 91 98 2000 91 98 4000 87 93 8000 80 87 A-weighted, dB(A) 97 103 each component making up the assembly. ... this manual, and their use for noise control purposes is of little value. When offered data in sones and phons, the noise control engineer should request the o...

Ngày tải lên: 13/08/2014, 05:22

... 199 2 Beranek, Leo L., Noise & Vibration Control, The Institute of Noise Control Engineering, Washington, DC, 198 8 Schaffer, Mark E., A Practical Guide to Noise and Vibration Control for HVAC Systems, ... & Vibration Handbook, 3rd Edition, McGraw-Hill, New York, NY 198 8 Beranek, Leo L. & Ver, Istvan L., Noise and Vibration Control Engineering, John Wi...

Ngày tải lên: 13/08/2014, 05:22

... System 9- 4 9- 1 Sound Levels for Equipment 9- 5 9- 1 CHAPTER 10. NOISE AND VIBRATION MEASUREMENTS Objective 10-1 10-1 Sound and Vibration Instrumentation 10-2 10-1 Measurement of Noise and Vibration ... Specification 9- 4 B-1. Bandwidth and Geometric Mean Frequency of Standard Octave and 1/3 Octave Bands B-6 UFC 3-450-01 15 May 2003 1 UNIFIED FACILITIES CRI...

Ngày tải lên: 13/08/2014, 05:22

... -7 -7 -7 -7 -7 -7 320 -6 -7 -8 -8 -9 -9 -9 -9 -9 500 -7 -9 -10 -11 -11 -11 -11 -11 -11 700 -8 -10 -12 -12 -12 -13 -13 -13 -13 1000 -8 -11 -13 -13 -14 -14 -15 -15 -15 2000 -9 -12 -15 -16 -17 -17 -17 -18 -18 3200 -10 ... initial condition of 91 dB. Therefore, the end condition TM 5-805-4/AFJMAN 32-1 090 should be 91 - 5 = 86 dB, which is confirmed in the column 8 of table 3-4 for th...

Ngày tải lên: 13/08/2014, 05:22

... -3 15 -12 +5 2.2 -4 20 -13 +4 2 .9 -5 25 -14 +3 3.7 -6 31 -15 +2 4.7 -7 40 -16 +1 6.1 -8 50 -17 0 7.7 -9 63 -18 -1 9. 7 -10 80 - 19 -2 12.0 -11 100 - 29 4-2

Ngày tải lên: 13/08/2014, 05:22

... (lb/ft. 2 ) 1 2 4 8 16 0 2 7 12 17 2 7 12 17 18 7 12 17 18 19 12 17 18 19 22 17 18 19 22 30 18 19 22 30 35 19 22 30 35 39 22 30 35 39 43 30 35 39 43 47 STC 18 21 24 28 33 Notes: 1. Surface weight based ... (in.) 4 6 8 10 12 Octave Frequency Band (Hz) 31 29 33 35 37 38 63 35 37 38 39 40 125 37 38 40 41 42 250 38 41 44 46 48 500 43 47 49 51 53 1000 48 53 54 56 57 2000 53 57 5...

Ngày tải lên: 13/08/2014, 05:22

... 65 67 70 79 90 1800 64 64 64 65 66 69 73 82 95 2000 65 65 66 66 68 70 74 85 99 2250 66 66 67 68 69 72 77 89 105 2500 67 67 68 69 71 74 79 93 110 2800 68 68 69 70 72 75 82 97 117 3150 69 70 71 72 74 ... 137 180 6500 76 77 79 82 86 94 108 143 1 89 7000 77 78 81 83 88 96 111 1 49 199 7500 78 79 82 85 89 98 115 155 208 8000 76 80 82 86 90 100 118 161 218 ket of snow are in...

Ngày tải lên: 13/08/2014, 05:22

... the architect and engineer to problems of noise and vibration. This is an important first step to noise control. Without awareness, the noise problem is ignored in the design, and later problems ... the various sources, fan noise will control the noise level in the low frequency range, air terminal units will control in the mid-frequency range, and air outlets will co...

Ngày tải lên: 13/08/2014, 05:22