| Advantages | Disadvantages |
| Audio Analyzer | Sound analysis system based on industry referencesComplete analysis softwareSupport digital audio testing | Bulky and occupy spaceExpensive and unsuitable for the production line applicationsTime-consuming and longer maintenance and verification cycle time |
| Sound Card | Low Price | Poor accuracy and design quality are prone to high false detection rate and maintenance rateObtaining imprecise testing results through Lower distortion and noise specifications is unable to meet high-end audio product testing needsThe different time differences lead to inconsistent and unstable test results when triggering analog inputs and analog outputs simultaneously |
| ADLINK Solution | PC-based architecture to easily integrate with other test functions and quickly complete automated testing system in production linesHigh 24-bit resolution, low distortion and low noise specifications offer more precise measurements to meet high-end audio product testing standardsComplete sound vibration testing applications through integrating with IEPE to directly connect microphone or acceleration sensorSynchronous trigger of AI and AO to enhance stability and consistency of audio loop back testingSignificantly reduce testing costs but better test performance/quality | The lack of complete analysis software, particularly as compared to traditional audio analyzerNo digital audio testing support |
# ADLINK Solution
ADLINK's PXI-9527, a 24-bit high dynamic signal acquisition card provides an excellent solution for audio loop testing of smart phones. As shown, the DUT audio input/output connects to the PXI-9527 via analog input/output channels, forming the testing loop. Via the mobile phone control program, the PXI-9527 analog output channel generates a swept sine wave from 20Hz to 20KHz, varying with mobile phones type, after which the signals are transmitted back to the PXI-9527's analog input channel, embodying test results of frequency response and distortion response after Fast Fourier Transform (FFT) processing, determining the DUT's audio quality. The PXI-9527 provides two analog input channels and two analog output channels capable of simultaneously detecting 3.5mm earphone audio circuit, speaker and microphone to fully satisfy multiple electro-acoustic device testing requirements. Expandability allows users to easily and quickly reconfigure test settings, such that if the number of electro-acoustic components to be tested changes, simply adding a switch or installing another PXI-9527 handles the variation, with no need to redesign the entire test system. The PXI-9527 also provides IEPE current output on each analog input channel, so no external power supply is required to power the microphone sensor, thereby simplifying system structure.
# Benefits
ADLINK's mobile phone audio testing solution provides more efficient implementation of audio testing systems and significantly reducing overall testing costs. The single-card solution providing complete signal output and collection rather than unidirectional and single-tone tests (only recording or broadcasting), significantly shortens the test cycle. With 24-bit precision, low distortion and low noise specifications, the PCI/PXI-9527 can stably and synchronously acquire AI and AO signals to ensure the accuracy and consistency of measurement results. Support for C/C++, .NET, LabVIEW, and diverse SDKs allows quick development of customized audio testing systems and flexible integration of other testing items. ADLINK also provides ready-to-use audio testing software enabling effortless testing system customization, reducing software development and system integration time and costs.
Audio Analyzer
Ready-to-Use Audio Testing Software
# Recommended Products
# PCI/PXI-9527
24-Bit High-Resolution Dynamic Signal Acquisition and Generation Module
# HiFi Mobile Phone Audio Testing
Mobile phones featuring High Fidelity (HiFi) technology experienced significant growth in 2014 and have driven increases in new product development, with manufacturers replacing conventional codec chips with advanced 192KHz/24-bit DAC and op-amp chips. Through audio, op-amp and other chips, sound quality of mobile phones can compare to 4X CD quality. HiFi technology will continue to be widely applied in mobile phones. As audio performance and quality are enhanced, challenges grow in audio testing. Upgraded function tests are required and can be realized by replacing low-end sound cards with more high-end audio test hardware.
# Application Requirements
Currently, commercially available sound cards (THD+N: -80 to -90dB, Noise level: 20 to 50 $\mu$ Vrms) are unable to satisfy the demands of HiFi measurement, such that manufacturers are required to access suitable 24-bit high precision, low distortion and low noise audio acquisition cards for production line testing with requirements are as follows:
\- Noise level referred to input < 3μVrms
\- THD+N (20Hz – 20KHz) referred to input < -95dB
# HiFi Mobile Phone Testing Items:
- Noise level testing: Acquisition of earphone output noise signals to verify compliance with specification, with standard values varying according to mobile phone model, normally 3 to $5\mu \mathrm{Vrms}$ .
- THD+N testing: Acquisition of earphone output single-tone signals at different frequencies (20Hz to 20KHz) to verify compliance of THD+N with specification, with standard values will varying according to mobile phone model, normally -90dB to -100dB.
# ADLINK Solution
For HiFi mobile phone audio quality testing, ADLINK provides the PCI-9527, connecting the phone's left and right sound tracks through its two analog input channels. After input measurement range is set at $\pm$ 0.316V, the PCI-9527 measures earphone output and compares the acquired values with original design specs, to evaluate DUT noise level. Further adjusted is input measurement according to the mobile phone's THD+N testing requirement, and earphone output single-tone signals are then tested at different frequencies (20Hz to 20KHz) using FFT to obtain THD+N measured values. Finally, DUT is tested for compliance with HiFi design standards.
Noise and THD+N Performance of the PCI-9527
# Benefits
The PCI-9527 provides 24-bit high precision and ultra-low distortion, accepting input signals as low as 3 $\mu$ Vrms and input THD+N (1KHz) to more than 100dB. Compared with standard sound cards often limited to measuring THD in -80dB or -90dB ranges, the PCI-9527 thoroughly fulfils key indicators in HiFi-enabled mobile phone testing, making it a clear market leader.
# Recommended Products
# PCI/PXI-9527
24-Bit High-Resolution Dynamic Signal Acquisition and Generation Module
# Car Navigation Audio Testing
To secure a position in the in-vehicle infotainment and navigation market, manufacturers are required to provide superior audio and video capabilities, while optimizing audio reproduction quality. What is required is a cost-efficient audio testing solution.
# Application Requirements
In-vehicle infotainment and navigation device manufacturers require audio testing systems that can quickly measure four audio output channels (including multiple speakers in various vehicle locations), analyzing audio quality and identifying device defects. Previously, manufacturers have largely relied on manual testing requiring extended testing times, utilizing expensive testing instrumentation, often with fewer output channels (usually only two), which further extends the duration of testing events. Lower testing costs and quicker processing turnaround are, accordingly, beneficial, with specific requirements including:
- Quick testing system setup providing a variety of automatic testing programs on production lines
- Increased bandwidth to shorten testing cycles and improve test efficiency
- Reduced cost of testing equipment
# > Car Navigation Audio Testing Items:
• Audio Output Level
• Crosstalk: <60 dB (1KHz)
• Frequency Responses: ±3dB (20Hz to 20KHz)
• Signal-to-Noise Ratio (SNR): 70dB (1KHz)
• Total Harmonic Distortion + Noise (THD+N): -60dB (1KHz)
• Dynamic Range: 70dB (1KHz)
# ADLINK Solution
ADLINK's PCIe-9529 24-bit high-precision signal acquisition module with dynamic range up to 110dB and eight input channels easily meets multi-channel vehicle navigation testing requirements, measuring Signal-to-Noise Ratio (SNR), THD+N, channel crosstalk, volume, primary frequency, and items. Eight 24-bit sampling analog input channels mean the PCIe-9529 can simultaneously measure two 4-channel devices, and included LabVIEW drivers allow quick development of in-house testing programs. As shown, PCIe-9529's eight analog input channels connect to two DUT soundtracks, after which FFT is used to obtain testing values including SNR, THD+N, dynamic range, and others, to effectively and quickly determine whether the DUT conforms to specific requirements.
# Benefits
Users can benefit greatly from ADLINK's PCIe-9529 multi-channel signal acquisition module, with shorter testing, improved efficiency, and significant time and manpower reduction, all with no requirement for expensive audio analyzers, thus significantly reducing overall costs of testing. With eight 24-bit sampling analog input channels, the PCIe-9529 can test two 4-channel devices simultaneously, shortening test cycles and enhancing efficiency. The SDKs support C/C++, .NET and LabVIEW, allowing quick development of required audio testing systems for automated production line testing, reducing time, effort, and cost.
# Recommended Products
# PCIe/PXle-9529
8-CH 24-Bit High-Resolution Dynamic
Signal Acquisition Module
# Machine Vibration Analysis
Industrial machinery is subject to nearly constant shock and vibration, creating fatigue and wear on materials and components. Imprecision and eventually system failure can result. Forecasting potential problems to implement preventive measures and maintenance or equipment replacement is critical to sustain performance and avoid downtime and costly damage. Machines or tools using a rotary axis, for example, frequently exhibit vibration and noise from unbalanced rotation. This imbalance reduces the life of shaft bearings, so a dynamic balance process is employed, using accelerometer and tachometer readings to calculate and adjust mass and deviation angle. Temperature and voltage readings can also be used to diagnose machine health.
Conventionally, data acquisition modules collect data from sensors on individual machines. Based on the data, portable vibration detectors check for potential problem machines one by one, a time-consuming and labor-intensive practice, with unavoidable errors and slow reaction times.
# Dynamic Rotor Balance Analysis
For rotary machines, unbalanced rotation can easily generate unacceptable vibration and noise, while reducing the lifetime of shaft bearings. The imbalance can be caused by effective displacement of the mass centre line from the actual axis of the mechanism. Especially in tooling machines, vibration caused by the imbalance can seriously affect machining precision. To avoid such vibration and noise, the imbalance is reduced using a procedure known as dynamic balance, in which an accelerometer and tachometer measure vibration frequency and rotary speed to enable calculation of the unbalanced mass and deviation angle. A DSA (dynamic signal acquisition) module with high resolution and wide dynamic range is implemented to receive output from the accelerometer and tachometer.
USB-2405 USB 2.0 DSA Module
# Predictive Diagnosis of Mechanical Faults
Performance of regular maintenance which periodically replaces aging or worn parts and consumables is the most common method to keep machinery working properly. In fact, however, differences in usage can lead to early damage of the components or speed depletion of consumptive materials, producing noise and vibration and reducing machine accuracy causing breakdown, or even industrial accidents. Abnormalities can be identified in advance by predictive diagnosis. In rotation machinery, for example, various rotating components exhibit characteristic frequencies that can be measured by accelerometer and spectral analysis. After long-term operation, mechanical parts, experiencing mild to severe wear and tear and mechanical aging will gradually produce vibration, with corresponding frequency values reflecting the change. Frequency comparison and analysis can identify components likely to fail, with preventive maintenance or replacement indicated accordingly.
Accelerometer
Microphone and Tachometer
# ADLINK Solution
The USB-2405 24-bit USB DSA, features 4 simultaneously sampling input channels accepting both accelerometer and tachometer data. Each channel provides up to 2mA excitation current to IEPE or ICP® sensors. With the library of the included Visual Signal DAQ Express utility, vibration frequency and rotary speed can be calculated precisely with no programming requirement, for further dynamic balance analysis. The ADLINK USB-2405, with included Visual Signal DAQ Express, includes powerful vibration analysis functions found in known sound and vibration analysis software:
- Viewer (channel, X-Y plot, time-frequency)
- Conversion (channel switch, time shift, resample, data selection,...)
• Filter(FIR/median/notch/moving average)
• Mathematics (RMS, sound pressure level, diff, mixer,...)
• Transform (FFT, IFFT)
• Time-Frequency Analysis (Short-term FFT)
Time-frequency
Channel Switch
Mixer
Multiplier
Resample
Time Shift
# Benefits
Visual Signal DAQ Express's visualization user interface allows acquisition and analysis of noise and vibration signals with no programming requirement, significantly reducing new project development time.
The ADLINK USB-2405 provides analysis functions similar to known sound and vibration analysis software, which can conserve development resources.
# Recommended Products
# USB-2405
4-CH 24-Bit 128kS/s Dynamic Signal
Acquisition USB 2.0 Module
# Dynamic Signal Acquisition Products for Diverse Platforms - Selection Guide
# PXI and PXI Express Platform
PXI's open hardware platform is specifically created for testing, measurement and control function, and supports the industry's highest bandwidth and lowest latency. ADLINK offers over 100 different PXI bus products for automation testing and measurement applications, including 3U/6U and 6-/19-slot host chassis, desktop or portable integrated chassis, and a variety of PXI instruments and modules, enabling easy integration of required test and measurement functions.
# PCI and PCI Express Platform
PCI/PCI Express is the most popular PC-based platform in the current industrial control field, and has the advantages of competitive price and diverse hardware choices. ADLINK offers a range of industrial computer systems, including rack-mount or wall-mount host chassis, and fanless embedded computers for high-performance embedded applications. These industry-leading products provide high-performance computing, high-speed scalable PCI/PCIe slots, and compact size to meet a variety of application needs.
# USB Data Acquisition Platform
With the high-speed USB standard and latest semiconductor technology, ADLINK provides flexible, modular, and easy-to-use USB dynamic signal acquisition platforms, ideal for portable testing and control applications.
# Dynamic Signal Analyzers Selection Guide
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