Reliable Hearing Aids with the Help of Industrial Computed Tomography
21.11.14 - A leading hearing instrument manufacturer uses the WENZEL Volumetrik exaCT S desktop computed tomography system for analyzing single components, modules and complete installed products. As a result of being able to nondestructively look inside the hearing instruments, quality assurance now becomes faster, more precise and more reliable.
The development of hearing instrument has a long history. Starting with the stethoscope through the first wearable hearing aid, which needed still a power connection, to the latest models which could be worn nearly invisibly due to their low weight and small size.
The increasing miniaturization affects every component of the hearing instrument like for example microphone, amplifier, loudspeaker and also the plastic casing which is produced by an injection molding process. Industrial computed tomography offers the best possibility of analyzing these small and complex components complete in their inner and outer structures and to check for defectives.
Wide range of applications
The hearing instrument manufacturer uses computed tomography for a lot of different things: So for example to check the quality of ongoing production, for the support of the start-up production, for the development of new hearing instruments or single components as well as for improvement in the quality of the injection molding of plastic components.
Completely installed hearing aids and small modules are often analyzed for correct assembly and for possible deformations while assembling the parts. At the single component level, the smallest structures and complex features can be measured. The tolerances are very tight, so the highest precision is required.
The decision for WENZEL Volumetrik exaCT S desktop computed tomography came after a rigorous selection procedure by the customer. The computed tomography has a closed and maintenance-free 130 kV x-ray tube with an industrial detector from WENZEL Volumetrik (resolution > 2 Megapixel). The highly accurate and granite-based mechanics of the computed tomography has been used successfully by WENZEL in the field of coordinate metrology for decades. With computed tomography, very high precision of less than 5 µm can be achieved.
Powerful software
Also very important was the selection of the powerful measurement and analysis software Metrosoft QUARTIS from WENZEL Metromec. The software enables the dimensional analysis of the data which was generated by the computed tomography.
The extensive functionality also includes the measurement of inner structures which can´t be accessed by tactile or optical measurement methods. In addition, fully automatic measurement processes for scanning numerous features can be created easily in only one step. The hearing instrument manufacturer uses Metrosoft QUARTIS to enforce a target-actual comparison against CAD data from small plastic components. A report is generated which makes every defect visible at one glance.
With the exaCT Analysis module varied and complex surface data can be processed. A concrete example is the 3D porosity analysis which gives information about the size, the distribution and the place of the blowholes. Easy to use export options ensure the direct data transmission to the extern statistic software qs-STAT from Q-DAS.
