🔬 Engineering Guide · IEC 60942 Accuracy Classes

Sound Level Calibrator Selector (IEC 60942): Regulated Class 2 Favorite Center 326, PTB-Approved Class 1 Reference & Verified B&K Classics

For every STIPA and PAVA measurement per IEC 60268-16, exact 94.0 dB SPL calibration is mandatory, as SNR and auditory masking penalties are level-dependent. Choose the ideal calibrator for your Bedrock SM50/SM90 test kit—from our best-selling closed-loop favorite to certified authority standards.

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When Is Class 1 (PTB Approval) Formally Mandatory?

When inspection codes formally mandate Class 1 precision for your analyzer (e.g., Bedrock SM90 / AM100), you must also use an IEC 60942 Class 1 calibrator (with official pattern approval for legal metrology). A Class 2 calibrator formally degrades the entire measurement chain to Class 2!

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When Class 2 Suffices (Physical Reality)

When no formal Class 1 obligation exists (as in standard commissioning with the Bedrock SM50), real-world differences between Class 1 (±0.2 dB) and a closed-loop Class 2 calibrator like the Center 326 are negligible. Crucial is an integrated reference mic with closed-loop feedback, keeping SPL rock-solid at 94.0 dB even with a 1/4" adapter!

Groups 1 & 2 · Configurator Options

Direct Comparison: Which Calibrator Fits Your PAVA Kit?

Budget Entry · Unregulated Catalog
Sound level calibrator AZ8930 incl. calibration certificate

Sound level calibrator AZ8930 incl. calibration certificate

Art. 7007 · IEC 60942 Kl. 2

94 / 104 / 114 dB @ 1 kHz incl. calibration certificate. Budget entry calibrator. Has no internal reference microphone (open-loop) and is sensitive to chamber volume variations. Verified in our lab before shipping.

Price: 121,85 € Net
incl. 19% VAT: 145,00 €
+ Optional Bedrock CNC adapter (Art. 7157): +31,50 € Net (37,49 € incl. 19% VAT)
⭐ OUR #1 RECOMMENDATION · CLOSED LOOP Catalog
Sound level calibrator Center 326

Sound level calibrator Center 326

Art. 7002 · IEC 60942 Klasse 2 (94 dB & 114 dB @ 1 kHz)
Proven in field use across PAVA installers
✓

True Active Closed-Loop Feedback: Built-in reference microphone in the pressure chamber compensates volume differences (e.g., from adapters or mic geometry) back to exactly 94.0 dB / 114.0 dB.

✓

Lab Precision Near Class 1 Level: In our lab audits, typical level deviation of the Center 326 is under ±0.2 dB—effectively matching Class 1 tolerances in practice.

Total (Center 326 + Adapter): plus shipping
308,50 € Net 367,12 € incl. 19% VAT
✓ Select Center 326 + Adapter in Configurator →
💎 Engineering Insider Tip · Genuine Class 1 ab 550,00 € Net (654,50 € incl. 19% VAT)

Lab-Verified Used Class 1 Classics: Brüel & Kjær 4231 (Green), B&K 4230 & Norsonic 1251

For accredited inspectors requiring Class 1 (e.g. on Bedrock SM90): Brand new Class 1 calibrators often cost well above €1,300 net. Our refurbished B&K and Norsonic units were built for decades of service and are individually audited and tuned on our Audio Precision APx555 prior to dispatch.

IEC 60942 Klasse 1 Catalog
Second hand Bruel&Kjaer 4230 Sound level calibrator class 1

Second hand Bruel&Kjaer 4230 Sound level calibrator class 1

94 dB @ 1 kHz. Robust analog classic with legendary precision. Includes 1" and 1/2" couplers.

550,00 € Net
654,50 € incl. 19% VAT
⭐ OUR LAB REFERENCE Catalog
Second hand Bruel&Kjaer 4231 Sound level calibrator class 1

Second hand Bruel&Kjaer 4231 Sound level calibrator class 1

94 dB & 114 dB @ 1 kHz. The worldwide Class 1 reference with internal 200V condenser mic. Exactly what we use on our APx555 test bench!

1150,00 € Net
1368,50 € incl. 19% VAT
IEC 60942 Klasse 1 Catalog
Second hand Norsonic 1251 Sound level calibrator class 1

Second hand Norsonic 1251 Sound level calibrator class 1

114 dB @ 1 kHz. Precision sound calibrator from Norway. Highly stable across frequency and temperature.

830,00 € Net
987,70 € incl. 19% VAT
🏛️ Group 4 · IEC 60942 Class 1 · Official PTB Pattern Approval (Legally Verifiable)

Brand New Class 1 Reference Calibrators with PTB Pattern Approval (Microtech Gefell & Svantek)

When your measurement chain requires official verification (weights & measures authorities) or PTB pattern approval is mandated for forensic expert reports, these two instruments are the benchmark.

PTB-BAUARTZULASSUNG · 2 FREQUENZEN Catalog
MTG Microtech Gefell  acoustic calibrator class 1 4010

MTG Microtech Gefell acoustic calibrator class 1 4010

Art. 7006 · Microtech Gefell

Class 1, PTB approved. Dual-frequency calibrator with 250 Hz & 1,000 Hz at 94 dB & 114 dB. Enables low-frequency response verification in addition to standard calibration.

1350,00 € Net
1606,50 € incl. 19% VAT
PTB-BAUARTZULASSUNG · 94 / 114 dB Catalog
Svantek SV30A class 1

Svantek SV30A class 1

Art. 7001 · Svantek

Class 1, PTB approved. Modern closed-loop MEMS reference system at 1,000 Hz with dual levels (94 dB & 114 dB). High stability against atmospheric pressure and temperature shifts.

1150,00 € Net
1368,50 € incl. 19% VAT
🔬 Group 5 · Specialized Calibrators (Multi-Level / Low-Frequency) & Calibration Service

Linearity & Low-Frequency Calibrators (AWA Multi-Level & Center 327) plus Calibration Service

For advanced acoustic testing, microphone linearity audits, and annual ISO 9001 calibration.

4 Pegelstufen (30 dB) Catalog
awa class 1 Mulitlevel 104dB 94dB 84dB 74dB

awa class 1 Mulitlevel 104dB 94dB 84dB 74dB

Class 1 (without PTB approval) with 4 level settings: 74, 84, 94, and 104 dB @ 1 kHz. Ideal for linearity verification across 30 dB dynamic range.

1200,00 € Net
1428,00 € incl. 19% VAT
125 Hz & 250 Hz Tiefton Catalog
Center 327 multi frequency 125Hz and 250Hz

Center 327 multi frequency 125Hz and 250Hz

Multi-frequency Class 2 calibrator for low frequencies: 125 Hz & 250 Hz @ 94 dB. Specifically designed for A/C weighting

459,00 € Net
546,21 € incl. 19% VAT
Unser Labor-Prüfstand

Factory & DAkkS Calibration

We calibrate sound calibrators of all brands (B&K, Norsonic, Center, Testo, Voltcraft, Cirrus) on our Audio Precision APx555 reference bench.

Factory Cal (S101): 50,00 € Net
59,50 € incl. 19% VAT
DAkkS-Kalibrierung: 349,00 € Net
415,31 € incl. 19% VAT
Inside the Pressure Chamber

Lab Teardown: Why Open-Loop Calibrators Drift When Geometry Changes

A sound calibrator produces sound pressure within a tiny acoustic chamber. If the chamber volume shifts due to capsule geometry or insertion depth, the sound pressure drifts—unless an integrated reference microphone measures the cavity in real-time and regulates the drive voltage.

Brüel & Kjær 4231 Teardown Referenzmikrofon
1. B&K 4231 (Klasse 1): True 200V precision condenser mic regulates chamber to ±0.2 dB.
Center 326 Teardown Regelkreis
2. Center 326 (Klasse 2, Art. 7002): Closed-loop chamber with internal reference mic.
AZ8930 Teardown ohne Referenzmikrofon
3. AZ8930 (Budget, Art. 7007): Digitally synthesized, but WITHOUT internal reference mic (open-loop).

* All prices in EUR Net excl. VAT and Gross incl. VAT plus shipping costs (FCA Dresden). B2B offer for commercial, government & professional users.