[clay68c10]

I use those temp guns as a second opinion type of confirmation. It can just confirm that the gauge isn’t way out of whack. It should read reasonably close to the gauge when you shoot it at the metal surface by the sender.
It also can be handy to see just how well your radiator is cooling. Check the temp difference between inlet and outlet hoses and compare that to a known good vehicle. You can also find cold spots by scanning the radiator surface.
If you think the radiator has blockage, get it rodded/cored or replace it. You should be running cooler than you are.