Testing CSS at different pixel densities

I need to simulate pixel density breakpoints. I use min-resolution and friends to test pixel density to determine what image to load in my CSS for things like headers and such.

But, I have found no solution to test my code at specific resolutions that mimics 1x, 1.5x, 2x, 2.5x etc. Do I need to own devices that run at those resolutions to test or is there an automated/non-automated solution to this?