|
|
|
Microphone Testing
|
|
The NTi Audio microphone test system is a comprehensive test solution with short test cycle times. The turnkey system is based on the high-speed FX100 Audio Analyzer and the dedicated production test software "RT-Microphone". It provides a comprehensive set of measurements for the total quality control of microphone components or final assembled products, such as mobile phones, vocal microphones, headsets or MEMS microphones.
Schematic Setup:
|
|
Key-Parameters:
- Accurate and repeatable measurements
- Turnkey solution with flexible user interface in selectable languages English, Chinese, Japanese, Korean, German
- Short test cycle time, typically < 2 seconds
- Dedicated for R&D and automated production lines
- Scalable test architecture with dual channel measurements and optional switchers for sequential testing of one or more microphones
- Built in phantom power supply
Flexible Parameter and Tolerance Setting
|
Test Parameter and Tolerance Setting
(click to enlarge)
|
Microphones naturally bear an error rate in production. Sorting out faulty devices in an early production stage is important, thus this increases the overall yield, reduces waste material and optimizes the quality of the manufactured goods. Important for a modern, state-of-the-art microphone test system are reproducibility, automation, speed and simplicity. The FX100 Audio Analyzer forms the microphone test system comprising exactly these features.
Measurement Functions:
- Frequency response in-axis, off-axis
- Sensitivity
- Distortion
- Signal-to-noise ratio S/N
- Detection of audible imperfections
- Directivity, polar plot
- Polarity
|
Polar Plot
|
Polar Plot
(click to enlarge)
|
The polar plot analysis with the NTi Audio precision turntable complements the microphone measurement system to an all-in-one solution. The polar diagram displays the directional characteristic related to the measurement frequency of the microphone. For detailed analysis, the measurement angles might be set in arbitrary resolution down to less than 1°.
The high-speed FX100 Audio Analyzer generates a series of fast sweep signals, covering the complete audio band from 5 Hz – 80 kHz, and turns the microphone to the configured angles between the sweeps. The measurement time halves by choosing the 180° mode, which mirrors the polar image. The polar plot graphics can be adjusted after the completed measurement, thus the microphone test system offers full flexibility for post processing.
|
Calibration and Recording of Reference Data
|
Recording of Reference Data
(click to enlarge)
|
The automated calibration (e.g. equalization of the reference speaker) is carried out with the measurement microphone M2010. Thereafter the smart “learn-mode” simplifies tolerance definition by feeding the system with a representative set of one or more “Golden Samples”. The flexible tolerance management automatically derives its tolerance Pass/Fail criteria. The system also supports up to five different quality clusters, which may be user-defined, such as “Excellent”, “OK”, “Acceptable”, “Class 3” and “Reject”. This allows the manufacturer to distinguish between quality classes.
System integration into existing production lines and the connection to host controllers is very simple. The extremely short test cycle time enables the microphone test system to easily cope with high volume production lines.
|
Microphone Test Production Mode
|
Production Testing Frequency Response
(click to enlarge)
|
The patented measurement algorithms have been optimized for factory noise immunity. This maximizes production line yield and allows conducting the same measurement in R&D as well as in the production floor. In the production mode the measurement results are compared with the defined tolerances. The individual results of each measured parameter are summarized into a class result. (e.g. Passed/Failed).
The measurement may be triggered by
- Operator, using the keyboard
- Serial number barcode reader
- DIO Input (e.g. PLC trigger signal or foot switch)
The measurement results are shown on the PC-screen, indicated at the digital I/O Output (e.g. driving red/green lamps or bin-sorter) and directly logged into Microsoft Excel xlsx-format.
|
|
| |
|
|
|
|
|
|
|
| Login |
|