Medium upholstered chair, unoccupied, front side of seat back 2.5 cm, average

PTB reference data

Original description

Material properties

Thickness: Seat back front 1 in, seat top 2 in, armrests solid

Application: seating

Mounting: unoccupied

Reverberation chamber (ASTM C423 / ISO 354)

Values per m² of audience area, not per chair or person.

NRC

0.65

derived from ISO 354 lab data

α_p nach ISO 11654

f (Hz)	125	250	500	1k	2k	4k
α_p	0.55	0.65	0.65	0.70	0.65	0.60

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

Free. No password required.

Value from the PTB table, not verified

NRC: 0.65 (derived from ISO 354 lab data)

Measured values as a table (1 measurement)

Medium upholstered chair, unoccupied, front side of seat back 2.5 cm, average: 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	0.65	0.54	0.64	0.66	0.70	0.67	0.61

Measured values as a table (1 measurement)

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

Last updated: 09/04/2026