Nor1525 — Secondary Acoustic Calibration
Secondary calibration of sound calibrators, SLMs & microphones with automated certificates, uncertainties & SI traceability.
Measurements
- Sound absorption coefficient (transfer-function method)
- Sound transmission loss (4-mic transfer matrix method)
- Surface impedance & complex reflection coefficient
- Dynamic density & bulk modulus; transfer matrix elements
- JCAL intrinsic parameters: porosity, flow resistivity, tortuosity, viscous/thermal characteristic lengths, static thermal permeability
Frequency ranges
- Low: 50–1600 Hz (Ø100 mm tube)
- High: 200–6400 Hz (Ø30 mm tube)
- Full: 50–6400 Hz (dual-tube set)
Material Testing
Bench-scale characterization of acoustic materials under normal incidence for R&D, QA and supplier qualification. Configure the tube (Ø100 mm low-frequency, Ø30 mm high-frequency) to cover 50–6400 Hz per ISO/ASTM methods.
Typical materials
- Foams, felts, fibers, textiles, MPPs
- Barrier/absorber laminates and liners
- Thin panels and composites
Results delivered
- Absorption coefficient \u03B1(f) and Transmission Loss TL(f)
- Surface impedance Zs, complex reflection coefficient
- Intrinsic parameters via JCAL: porosity, flow resistivity, tortuosity, viscous/thermal characteristic lengths, static thermal permeability
Methods & QA
- ISO 10534-2 / ASTM E1050 (transfer-function method)
- ASTM E2611 (4-mic transfer matrix for STL)
- QA checks: leakage/phase checks, repeatability, attenuation correction
- Exports: CSV / Excel, direct export to MSC Actran
Software highlights
- Barrier & absorber properties: transmission loss, impedance, wave number
- Random-incidence absorption estimation models
- Tube attenuation removal; conical-adapter correction for STL
- Amplitude/phase calibration of microphones
- Selectable frequency resolution, averaging
- ASCII / Excel™ export; direct export to MSC Actran
System components
| Component | Specification |
|---|---|
| Analyzer | 102.4 kS/s, 100 dB dyn. range, 0.8 Hz resolution, 4-Input / 1-Output (NI-USB-4431) |
| Microphones | GRAS measurement mics, 10 Hz–20 kHz, 33–142 dB(A), 9 mV/Pa |
| Tubes | LF-ABS Ø100×945 mm; LF-STL Ø100×1130 mm; HF-ABS Ø30×875 mm; HF-STL Ø30×925 mm |
| Amplifier & Speaker | Built-in 20 W amplifier; full-range 4 Ω speaker |
| Calibrator (opt.) | Nor1256 (94/114 dB; 250 Hz/1 kHz; IEC 60942 Class 1) |
| Accessories & Docs | Ultra-low-noise cables, demo foam, transport case, QTR, cal certificate, manual |
Configuration options
| Range | Type | Tube | Mics | Code |
|---|---|---|---|---|
| 50–1600 Hz | Absorption (SAC) | Ø100 mm | 2 | Nor1527/LF-SAC |
| 50–1600 Hz | Transmission Loss (STL) | Ø100 mm | 4 | Nor1527/LF-STL |
| 200–6400 Hz | Absorption (SAC) | Ø30 mm | 2 | Nor1527/HF-SAC |
| 200–6400 Hz | Transmission Loss (STL) | Ø30 mm | 4 | Nor1527/HF-STL |
| 50–6400 Hz | Absorption + STL (dual-tube) | Ø30 + Ø100 mm | 4 | Nor1527/LF-HF-SAC/STL |
Complies with ASTM E1050, ASTM E2611, and ISO 10534-2.