envelope test

This paper analyses the difficulty in potentiometers' Contact Resistance Variation (CRV) test, and introduces an effective test method-Qarsi-Envelope test method (QETM).

Test pilots try to push the envelope.

To test this possibility, Bieniasz's team engineered an unrelated mouse retrovirus coated with the envelope protein that would have allowed the ancient chimpanzee virus to slip into cells.