Known failure cases: Understanding the Limitations of Our Application

As part of our commitment to transparency and continuous improvement, we are actively collecting and documenting failure cases encountered in our application. These cases include both false positives and false negatives, which highlight the limitations of our app’s performance.

By sharing these known failures, we aim to provide our users with a comprehensive understanding of the boundaries and constraints of our application’s capabilities. This transparency enables users to make informed decisions and manage expectations accordingly.

case_2022 Fake trade dollar

Specification (vs. genuine)

Coin The fake A genuine
Diameter 38.07mm 38.03mm
Weight 27.2g 27.0g
Content 78% silver core with 90% silver coating 90% silver
Test result* 2 stars 2 stars

*Result is provided on app version 0.12.?


Differentiating a fake coin closely mirroring the precious metal content of a genuine one presents a challenge during the sound test. This particular fake coin falls near the test’s limit, complicating the distinction.

This limitation has been mentioned here.

case_2023.3 Fake 1 franc

Specification (vs. genuine)

Coin The fake A genuine
Diameter 23.03mm 22.98mm
Thickness 1.29mm 1.26mm
Weight 3.51g 4.87g
Content Tin 83.5% silver
Test result* 3 stars 3 stars

*Result is provided on app version 1.3.11


Coins crafted from tin and from silver may produce similar sound components when they share the same shape. However, their distinct weight serves as a crucial differentiating factor. To ensure accurate identification, it is essential to carefully consider the weight of the coins.

This emphasizes the importance for users to verify both the size and weight of the coin before conducting tests. Section Common mistakes & Best practices may provide further information.

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