ASCEE proudly presents μZ, a state-of-the-art impedance tube designed for precise acoustic testing of small materials. μZ is ideal for researchers and engineers working with small acoustic material samples.
Key Features
- Includes all necessary software and hardware for seamless operation
- Very wide frequency range of 20 – 8,000 Hz
- Innovative rapid calibration method, without the need to switch microphones
- Best-in-class MEMS microphones with small acoustic ports do not disturb the sound field and enable a small tube diameter
- Compact size, yet 20 Hz capable
Applications
- Hearables
Characterize acoustic elements such as meshes, membranes and vents - Sound absorption measurement
Evaluation of the normal incidence sound absorption coefficient of small samples - Quality control
Monitoring and ensuring consistent quality of acoustic products
High Series Impedance Measurement Capabilities
By adding a microphone to the tip of the impedance tube, μZ can be used to characterize small acoustic meshes and membranes, with active diameters in the order of 1 to 3 mm. This type of materials is typically used in hearables, such as hearing protection and earbuds.
In the high-impedance configuration, μZ is capable of measuring series impedances up to 1 GPa·s/m³. This is approximately 3100 MKS Rayls for samples with an active diameter of 2 mm.
The sample holder that's included with the μZ system will be customized based on the desired measurement range and the samples under test, to optimize the system's performance for your application.
The figure on the right shows measurement data obtained from 5 samples of the same type of protective membrane. The measured impedance curves allow characterization of several material parameters, like the parasitic leakage, the compliance, the resonance frequency and damping.
Measurement Capabilities
Measuring acoustic quantities at high standing wave ratios challenges conventional measurement procedures, e.g. based on the EN-ISO 10534-2:2023 standard. This capability is essential for reliably assessing the impedance of "almost-hard walls" or materials with high transmission loss. Our innovative approach utilizes 4 MEMS microphones and an advanced calibration technique to determine the positions and sensitivities of the sensors. High impedance measurements add a 5th MEMS microphone to capture the transmitted sound.
The top figure illustrates the measured input impedance of a 200 mm long tube with a hard end cap, measured with our 20 mm inner diameter tube. The impedance exhibits a dynamic range of nearly 80 dB, highlighting the challenges of measuring at high standing wave ratios. The frequency range is 20 Hz - 8,000 Hz.
The bottom figure displays the computed normal incidence sound absorption coefficient (α) of the hard end cap. As shown, the computed α remains close to 0 over the entire frequency range of 20 – 8,000 Hz. This result is based on a single measurement. Note that, at 20 Hz, the wavelength in air is approximately 17 m, while our maximum microphone distance is only ~ 200 mm, which is significantly less than λ/10. Despite this, μZ still achieves good results at this frequency.
Scope of Delivery
- Transport case
- µZ measurement system
- 5 microphones
- Sample holders
- USB audio interface
- All required cables
- Software license
Software
A license for our proprietary software ACME is included. All calculations and a calibration wizard are contained in a µZ module.
Click to view: µZ userguide
Datasheet
Click to download: µZ-20 datasheetContact & Customization Options
Did we spark your interest? Or is the current μZ Impedance Tube system not quite what you need? We offer customization options to tailor the system to your specific requirements. Our team of experts is highly knowledgeable and skilled in the field of acoustics, ensuring that we can provide solutions that meet your unique testing needs.
Feel free to reach out to discuss your requirements, and let us help you design a system that perfectly fits your application. Whether you need modifications to the hardware, software, or specific features, we are here to assist you.
