NC - Noise Criterion Calculation
A machine
	Octave Band Center Frequency (Hz)
	63	125	250	500	1000	2000	4000	8000
NC-70	83	79	75	72	71	70	69	68
NC-65	80	75	71	68	66	64	63	62
NC-60	77	71	67	63	61	59	58	57
NC-55	74	67	62	58	56	54	53	52
NC-50	71	64	58	54	51	49	48	47
NC-45	67	60	54	49	46	44	43	42
NC-40	64	56	50	45	41	39	38	37
NC-35	60	52	45	40	36	34	33	32
NC-30	57	48	41	35	31	29	28	27
NC-25	54	44	37	31	27	24	22	21
NC-20	51	40	33	26	22	19	17	16
NC-15	47	36	29	22	17	14	12	11
0.5M	72.2	69.7	71.4	64.3	62.8	59.7	51.7	46.3
1M	73.1	69.3	72.5	63.2	61.3	58.3	51.3	45.6
1.5M	70.6	69.3	70.3	64.4	61.4	57.9	51.2	44.9
Mean value	72.09	69.44	71.5	64.0	61.9	58.7	51.41	45.64

   Use the above materials to surround A machine (2x3m) to reduce (db). How should it be calculated?

Transcribed Image Text:

Ruukki acoustic cladding 100 mm on both sides of wall 1. Ruukki acoustic cladding 100 mm on both sides 2. Ruukki sandwich panel (SPA 150E) used as internal wall 2 For internal wall usage in both sides, sound absorption coefficients (a) for rooms are same as with single 100 mm surface. Airborne sound insulation value improvement with typical SP-wall: - +16dB Ruukki acoustic cladding 100 mm on both sides of wall 1. Ruukki acoustic cladding 100 mm on both sides 2. Ruukki sandwich panel (SPA 150E) used as internal wall 2 For internal wall usage in both sides, sound absorption coefficients (a) for rooms are same as with single 100 mm surface. Airborne sound insulation value improvement with typical SP-wall: - +16dB

Answer rating: 100% (QA)

To calculate the noise level reduction achieved by surrounding the machine with the specified acoust... View the full answer