If you want to try this on your own setup, you don't need expensive calibration hardware. The digital community has created excellent resources:
Fine horizontal and vertical lines should be distinct without "flickering" or blurring. Identifies non-functioning sub-pixels. 4k testbilder
A simple black and white checkerboard grid is a classic test, but in the 4K era, it serves a specific, critical purpose: If you want to try this on your