A reference for acoustic engineers, NVH specialists, and R&D scientists who need decision-grade acoustic and vibration data. This guide covers instrumentation, workflows, and integration patterns drawn from Durham Instruments’ Brüel & Kjær (HBK) portfolio and proven measurement practice.
What’s Covered
Why reliable acoustic and vibration data is hard
Sound and vibration are deceptively easy to measure and very hard to measure well. The signal of interest is often only a few decibels above the noise floor of the measurement system, and small errors anywhere in the chain, a mismatched preamp, an under-rated cable, a poorly mounted accelerometer, turn what should be a definitive answer into a debate. Decision-grade data requires alignment of three things: the right instrument class, a workflow that controls the variables you can control, and documented traceability to recognized standards.
Durham Instruments has supported Canadian acoustic and vibration teams since 1977 and is the authorized Canadian partner for Brüel & Kjær (HBK). The lineup spans Class 1 sound level meters and arrays, head and torso simulators, vibration exciters, condition monitoring systems, and the LAN-XI / Fusion-LN front ends that capture the data.
Class 1
Sound level meter compliance (HBK 2245, 2255)
20 kHz
Full audible range with HBK Type 5128-C HF HATS
HBK Partner
Authorized Brüel & Kjær Canada coverage
ISO 9001:2015
Certified quality management
Measurement classes you actually need to choose between
“Acoustic and vibration” is too broad to specify against. Before you compare datasheets, decide which of the four measurement classes you are working in, the choice changes almost every downstream decision.
| Measurement class | Typical objective | Common instrumentation | Critical parameters |
|---|---|---|---|
| Product / NVH | Characterize a device under test, support design iterations | HF HATS (Type 5128-C), arrays, microphones & preamps, modal exciters, LAN-XI / Fusion-LN | Frequency range, repeatability, fixturing, signal-to-noise |
| Environmental / occupational | Verify compliance against regulation or contract | HBK 2245, 2255 sound level meters | Class rating, calibration, weather correction, log integrity |
| Building acoustics | Reverberation, sound insulation, intelligibility | HBK 2255 source & receiver mics | Source repeatability, room conditioning, post-processing |
| Industrial vibration / condition monitoring | Detect mechanical faults, support predictive maintenance | Permanent and portable monitors | Threshold setting, trend stability, alarm logic |
Class first, then product. Many measurement disputes trace back to using a single instrument across two classes, for example, an environmental sound level meter pressed into product development work it was never optimized for. Specify the class, then specify the product.
Instrumentation: from microphone to analyzer
An acoustic and vibration measurement chain is only as accurate as its weakest link. The four building blocks below need to be specified together.
1. Transducers
- Measurement microphones, pressure-field, free-field, or random-incidence depending on source geometry
- Accelerometers, IEPE, charge mode, or MEMS, sized to the frequency band and dynamic range
- Specialized devices, head and torso simulators (HATS), sound intensity probes, surface-mounted vibration sensors
2. Preamplifiers and conditioning
Microphone preamps must match the microphone polarization and capacitance. Accelerometer conditioning must match the sensor type, IEPE / CCLD current source, or charge amplifier for charge mode. Mixing these is a common cause of corrupted data on the first day of a campaign.
3. Front ends and DAQ
HBK LAN-XI and Fusion-LN are networked acoustic and vibration front end widely used for NVH; QuantumX covers mixed-sensor labs especially in mechanical testing; Genesis HighSpeed handles transient and high-bandwidth events most often for highly dynamic mechanical or electrical phenomenon. See the data acquisition catalog for current modules.
4. Software and post-processing
Octave and 1/3-octave analysis, FFT, order tracking, modal analysis, and intensity mapping each require specific software capabilities. Software fluency in your team is part of the instrumentation decision.
Repeatable workflows for product, environmental, and condition data
Equipment alone does not produce repeatable measurements. The discipline that surrounds it does.
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Plan
Define the question, the acceptance criterion, and the report format before the test. Decide what counts as a valid measurement and what disqualifies one.
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Configure
Document microphone class, preamp pairing, accelerometer mounting method, sample rate, anti-alias filter, and weighting. Save the configuration as a template for future campaigns.
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Calibrate
Perform a calibration check at the start and at the end of each measurement session. Record both results and flag any drift greater than your acceptance threshold.
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Capture
Record raw, unweighted, unfiltered data wherever bandwidth permits, you can always apply filters in post-processing, but you cannot recover what you discarded at capture.
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Validate
Inspect data for clipping, dropouts, and obvious environmental contamination before leaving the test site. Disagreements weeks later about whether a measurement is valid are very expensive.
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Document
Capture serial numbers, calibration certificates, environmental conditions, and operator. Reports without this information cannot be audited and are hard to defend.
Standards, traceability, and uncertainty
Decision-grade reports cite the standard the measurement was performed against, the traceability of each instrument’s last calibration, and an estimated uncertainty. Durham Instruments operates under ISO 9001:2015 and offers traceable calibration services for acoustic sensors, accelerometers, torque transducers, and reference instruments.
Common standards reference list. Sound level meters: IEC 61672. Microphones: IEC 61094. Building acoustics: ISO 16283. Environmental noise: ISO 1996. Mechanical vibration / condition monitoring: ISO 10816 / ISO 20816. Workplace noise: ISO 9612. Confirm the version applicable to your jurisdiction and project.
Deep-dive cluster guides
Five focused guides expand on the most frequently requested topics in this domain.
Type 5128-C High-Frequency HATS
Applications, fixturing, and calibration for the HBK Type 5128-C HF HATS in product development and telecom acoustics.
Read guide →
Sound Level Meters & Arrays
Field-ready techniques for environmental, occupational, and building acoustics with HBK Class 1 instrumentation.
Read guide →
Industrial Vibration Monitoring
Setting thresholds, routes, and alarm logic for predictive maintenance programs that reduce unplanned downtime.
Read guide →
Microphone & Preamplifier Pairing
How to preserve dynamic range and stability across microphone-preamp chains in aerospace and automotive testing.
Read guide →
Shakers & Exciters Framework
Selecting and configuring electrodynamic shakers and modal exciters for structural and dynamic characterization.
Read guide →
FAQ
What is a Class 1 sound level meter, and when is it required?
Class 1 refers to the most stringent accuracy class in IEC 61672 for sound level meters, with tighter tolerances on frequency response, directionality, and linearity than Class 2 instruments. Class 1 is generally required for environmental compliance work, regulatory acoustic measurements, building acoustics, and most product certification activity. Durham Instruments supplies the HBK 2245 and 2255 series, all Class 1.
Why does the Type 5128-C HATS exist if older HATS already cover speech bandwidth?
Older HATS were optimized for telephone-band measurements (up to roughly 8 kHz). The HBK Type 5128-C extends that to 20 kHz with an MRI-derived ear canal geometry and matched ear simulators, which makes it suitable for modern smart speakers, premium headphones, hearing protectors, and high-bandwidth audio devices where extended-range fidelity matters.
What is the difference between modal exciters and electrodynamic shakers?
Both move structures with controlled force. Electrodynamic shakers are sized for systems-level vibration testing, qualifying components or assemblies against vibration profiles. Modal exciters are smaller, optimized for clean force injection at a single point during modal analysis, where the goal is to identify resonances and mode shapes rather than to reproduce a service environment.
How often should acoustic instruments be calibrated?
Field calibration with a sound calibrator is performed at the start and end of every measurement session. Periodic laboratory calibration is typically annual, though regulatory bodies and contract requirements may demand shorter intervals. Durham Instruments offers traceable calibration through OEM laboratories and certified partners.
Can Durham Instruments help integrate a complete NVH or condition monitoring system?
Yes. Durham Instruments scopes complete acoustic, vibration, and condition monitoring systems, transducers, conditioning, DAQ, and software, and supports installation, calibration, and ongoing service from offices in Oakville, Montreal, and Edmonton. Contact our team with your application specification.
Plan your acoustic and vibration program
Talk with a Durham Instruments engineer about a complete measurement workflow, Class 1 instrumentation, accelerometers, front-end DAQ, and analysis software, sized to your application and standards.