Rockwool blanket, 2 inch thick batt, with 3/16 inch perforated Transite board

PTB reference data

Original description

Material properties

Thickness: 2 inch (Rockwool), 3/16 inch (Transite)

Wall distance: 1 inch

Perforation: 11%

Backing: Rockwool blanket

Surface: perforated cement asbestos board (Transite)

Reverberation chamber (ASTM C423 / ISO 354)

NRC

0.80

derived from ISO 354 lab data

α_p nach ISO 11654

f (Hz)	125	250	500	1k	2k	4k
α_p	0.40	0.75	1.00	0.85	0.60	0.50

Create a permanent free account — Access frequency bands, variants and export.

Free. No password required.

Value from the PTB table, not verified

NRC: 0.80 (derived from ISO 354 lab data)

Measured values as a table (1 measurement)

Rockwool blanket, 2 inch thick batt, with 3/16 inch perforated Transite board: sound absorption coefficient αs per ISO 354 by frequency and test build-up
Build-up	NRC	125 Hz	250 Hz	500 Hz	1000 Hz	2000 Hz	4000 Hz
Measurement 1	0.80	0.39	0.77	0.99	0.83	0.58	0.50

Measured values as a table (1 measurement)

Access frequency bands, variants and export. Create a permanent free account

Last updated: 08/28/2026