temp gun & digi therm cannot agree

[pet_snake_78]

I am measuring the same spot on substrate above the flexwatt with the accurite digitherm probe and an analog therm setting directly on the substrate surface and getting mid 80s. I then scan the same again with the HDE temp gun and get 75 degrees, Sometimes it also shows parts of the cage as 65 but the room is 78F according to both the analog devices and 2 digitherms. I bought a second accurite because I thought maybe the first one was bad. Do your probes set directly on the substrate and your temp gun usually vary that much, with the temp gun showing 10F lower? I can see the temp gun definitely knows when something is warmer or cooler but I'm questioning it's accuracy.