SoundFlow Sensor
Simultaneous Pressure + Particle Velocity Measurement — 20 Hz to 15 kHz in One Scan
The SoundFlow is a PU (pressure–velocity) acoustic intensity probe that measures sound pressure and particle velocity at the same time. Unlike classical PP probes, it covers the entire acoustic range from 20 Hz to 15 kHz in a single measurement — with no spacer swaps, no extra setup.
Key Specifications
Frequency Range
20 Hz – 15 kHz
Dynamic Range
25 – 130 dB(A)
Source Separation
> 40 dB
Probe Head Diameter
< 4 cm
Power Supply
ICP (DAQ supply)
Standards
ISO 9614-1 / -2
Why the SoundFlow Sensor?
A different approach to sound intensity — faster, smaller, more precise
Simultaneous P + V Measurement
Measures sound pressure and particle velocity at the same point, same instant. True sound intensity is computed directly — no approximation, no time-averaging artefact.
Full Acoustic Range in One Scan
Classical PP probes need spacer changes to cover 20 Hz to 5 kHz vs 5 kHz to 10 kHz. The SoundFlow covers 20 Hz–15 kHz in a single measurement pass — saving setup time and reducing error.
Ultra-Compact: Under 4 cm Diameter
The probe head is significantly smaller than classical intensity probes. It fits close to surfaces and into tight spaces where conventional probes cannot reach.
High Source Separation (> 40 dB)
The directional nature of particle velocity provides >40 dB separation of sound sources across the full frequency range — essential for identifying which component is the dominant noise source.
ICP Powered — No Special Supply Needed
Runs on the standard ICP supply of any data acquisition system. No dedicated power unit required — plug in and measure.
Complete Software Ecosystem
Works with siIntense for sound power mapping, siSourceView for video-overlay near-field scanning, and siCamera for low-frequency intensity imaging — all from Soundtec.
Applications
From R&D lab to production floor
Sound Power Measurement (ISO 9614-1 & -2)
Scan an enveloping surface around any source — even in the presence of background noise — to determine total radiated sound power per ISO 9614-1 (discrete points) or ISO 9614-2 (scanning). Works in ordinary rooms without anechoic or reverberant chambers.
Near-Field Sound Radiation Mapping (siSourceView)
Scan the surface of any object with the SoundFlow while a video camera tracks the probe position automatically. The measured intensity is displayed as a colour overlay on the video image — making sound radiation directly visible with minimal effort.
Automotive NVH
Identify which panel, gasket, or drivetrain component is the dominant noise contributor in a vehicle interior or under-hood. The >40 dB source separation ensures reliable identification even with multiple competing sources.
Industrial Machinery & HVAC
Locate bearing noise, gear mesh tones, fan blade pass frequencies, or duct radiation in operating machinery — without shutting down the line. Sound power measurements satisfy regulatory noise emission reporting.
R&D & Product Development
Compare prototype variants, validate design changes, or characterise noise sources across the development cycle. The compact PU probe integrates into test rigs and enclosures where traditional intensity probes do not fit.
SoundFlow vs Classical PP Intensity Probes
| Feature | SoundFlow (PU) | Classical PP Probe |
|---|---|---|
| Measurement Principle | Pressure + Particle Velocity (direct) | Two-microphone pressure (approximation) |
| Full Range Coverage | 20 Hz – 15 kHz in one setup | Requires spacer change (multiple setups) |
| Low-frequency accuracy | High — direct velocity sensor | Limited by microphone phase mismatch |
| Probe Head Size | < 4 cm diameter | Larger — limited near-surface access |
| Source Separation | > 40 dB (full range) | Reduces significantly at low frequencies |
| Power Requirement | Standard ICP supply | Standard ICP supply |
| Phase Calibration Required | No | Yes — critical for accuracy |
Technical Specifications
| Parameter | Value |
|---|---|
| Measurement Type | Sound Pressure + Particle Velocity (simultaneous) |
| Frequency Range | 20 Hz – 15 kHz |
| Dynamic Range | 25 – 130 dB(A) |
| Source Separation | > 40 dB across full frequency range |
| Probe Head Diameter | < 4 cm |
| Power Supply | ICP (from DAQ system — no separate unit required) |
| Self Noise | Low — maintained across high frequencies |
| Applicable Standards | ISO 9614-1 (discrete), ISO 9614-2 (scanning) |
| Compatible Software | siIntense, siSourceView, siCamera |
| Manufacturer | Soundtec GmbH, Göttingen, Germany |
Software Ecosystem
Three tools, one sensor — complete sound radiation workflow
siIntense
Sound intensity measurement and sound power determination by mapping the enveloping surface of a source. Full ISO 9614 workflow with automatic power integration.
siSourceView
Near-field sound radiation scanner with video-overlay visualisation. One sensor + one camera: scan any object and see the intensity map displayed directly on the video image. Identify frequency-selective and tonal sources at a glance.
siCamera
Acoustic camera for low-frequency sound intensity imaging very close to the object — the only way to obtain precise spatial maps of radiated sound energy at frequencies below 500 Hz. Extends the acoustic camera principle to where beamforming fails.
Frequently Asked Questions
What is a PU intensity probe and how does it differ from a PP probe?
A PU probe measures sound pressure (P) and particle velocity (U) directly and simultaneously using separate sensors. Classical PP probes approximate intensity using the pressure gradient between two microphones, which introduces phase errors — especially at low frequencies. The PU approach gives more accurate results across the full frequency range and eliminates the need for spacer changes.
Does the SoundFlow require an anechoic or reverberant test chamber?
No. Sound power measurement with the SoundFlow sensor per ISO 9614 can be performed in ordinary rooms — production floors, workshops, or engineering labs. The high source separation (>40 dB) means background noise has minimal effect on the measurement.
What data acquisition system does the SoundFlow connect to?
The SoundFlow uses a standard ICP (Integrated Circuit Piezoelectric) supply, which is available on virtually every professional DAQ system. No dedicated power unit is required. It outputs signals directly to the DAQ input channels.
How does siSourceView show where the noise is coming from?
A video camera tracks the position of the SoundFlow probe as you scan the surface of the object manually. The siSourceView software correlates sensor position with the measured intensity values and builds a colour map overlaid directly on the video image — in real time. You can filter by frequency or select specific tonal components to identify individual contributors.
What is the advantage of siCamera for low-frequency noise?
Conventional acoustic cameras based on microphone arrays and beamforming lose spatial resolution at low frequencies because the array would need to be impractically large. The siCamera uses close-field intensity measurement with the SoundFlow sensor, which is effective regardless of frequency — making it the only practical tool for imaging sound radiation below 500 Hz with high spatial resolution.
Is the SoundFlow Sensor available in Thailand and Southeast Asia?
Yes. Placid Asia is the authorised representative for Soundtec products in Thailand and the ASEAN region. We provide the SoundFlow sensor with local application support, measurement consultation, and after-sales service from our Bangkok office.
Get the SoundFlow Sensor for Your Application
Contact Placid Asia for pricing, technical consultation, or a live demonstration of the SoundFlow sensor and siSourceView software. Our acoustic engineers will help you select the right measurement setup for your specific application.