marginal test

marginal test

[′mär·jən·əl ′test]
(electronics)
A test of electronic equipment in which conditions are varied until failures occur or faults can be detected, allowing measurement of permissible operating margins.

marginal test

A system test that introduces values far above and far below the expected values.
References in periodicals archive ?
On the other hand, marginal test results or outright failure should set off warning bells.
This makes an already (in my opinion) borderline marginal test little better than a coin flip.