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POWER PLANT ACOUSTICS Episode 6

Tham khảo tài liệu 'power plant acoustics episode 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | TM 5-805-9 AFM 88-20 NAVFAC DM-3.14 ROOM CONSTANT BY ESTIMATION METHOD Room name or Nof VSOTVE J OOA- Va. 2__ 1. Average room dimensions ft. Length Sb Width SA Height __30 2. Total interior surface area s of room 3y-0t ft.2 3. Volume of room L õ b o ft.3 t. Area s of planned acoustic treatment 2. OOP ft.2 Add 50 of carpet area to Item h value if floor is carpeted and 30 of frontal area of any heavy drapes or upholstered furniture. Do not include unit absorbers or hanging baffles in Item u but add their total sabins into Item 13 summary. 5. Area s of room surfaces less than 3 -in. thick Z Z 8 ft.2 thin ----- ------- 6. Percent area covered by acoustic treatment s s X 100 2. Ì 7. Percent area of thin boundary surfaces x 100 8. Room Constant from figure 5-2 for room volume 2 of Item 3 and 0 area acoustic coverage RQ ft.2 Note For no acoustic treatment in room ignore Items 9 10 11 go to Item 12. 9. Room Constant from figure 5-2 for room volume of J Item 3 and percent acoustic coverage of Item 6 Rac Cs CJ ft.2 Note Item 9 value is taken to apply for lOOO-oOOO Hz bands. 10. Acoustic treatment NRC spec range 0.1 to AIMA mounting type 1 I iz f 7 I I 11. Low frequency multiplier and Room Constant attributable to acoustic material. Obtain multiplier from Part A of table 5-3 and insert in Col. 2. Multiply Col. 2 value by Item 9 Room Constant insert in Col. 3. 12. Low frequency multiplier and Room Constant attributable to thin room surfaces. Obtain multiplier from Part B of table 5-3 for percentage value of Item 7 and insert in Col. 2. Multiply Col. 2 value by Item Room Constant Col. 1 Col. 2 Col. 3 Col. 1 Col. 2 Col. 3 Frequency 31 IT Low frequency Frequency 31 Multiplier A Low frequency Constant 63 63 A 125 9 go 125 A SBb 250 80 250 AS sso 500 . g J gyp 500 AD 5 3 13. Summary Room Constant for all octave bands ft.2 For no acoustic treatment .