Tests to check quality of mask

These simple tests help determine whether your mask is effective or not. 

Times of India: Coronavirus: If your mask doesn't pass these three tests, it is not helping.

https://timesofindia.indiatimes.com/life-style/health-fitness/health-news/coronavirus-if-your-mask-doesnt-pass-these-three-tests-it-is-not-helping/photostory/80894265.cms