Sensors::Mean Time To Failure

The MTTF (Mean Time To Failure) cannot be exactly determined with the strain gauge sensors.

The fatigue strength depends on many factors:

- on the component itself (design, material... etc.)

- on the environment (humidity, temperature... etc.)

- on the operating conditions (load amplitude, number of load cases, swelling load, changing load, ...)

We lay out most of our sensors with an output signal of 1 mV/V. This corresponds to strain of 500 µm/m, or a mechanical stress on the strain gauge of 36.5 N/mm² for aluminum, or 105 N/mm². This means that the sensors and strain gauges are clearly dimensioned in the permanently stable range.

Influence of the load

Similar to metallic materials, there is an influence on the amplitude and the type of load, e.g. swelling or changing load.

Up to a strain of 1000 microns/m, more than 10E6 load changes can be achieved, with 500 microns/m one usually achieves fatigue strength.

Influence of processing

The decisive factor for achieving fatigue strength is fault-free processing with soldering support points and a strain relief loop with strand AWG36... AWG30 and cover with appropriate covering agents.

 

Experience has shown that our sensors achieve an operating life of 20 years or more thanks to a safe adhesive wiring and casting process.

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