Newbie heating help!

I am a new beardie owner as of 4 days ago. I adopted him from someone who was moving across the country. He is a 3 year old adult and is such a love bug. My questions is about his heat situation. Currently he is in a 40 gallon tank. I have an 18" UVB strip on one side and on the other I have a 150 Watt basking (UVA) lamp over his elevated rock. I was under the impression that 150 Watts would be sufficient to get his tank temp up to 100 degrees, but every time I take the temperature it's all over the place. I am reading the temp with a ReptiTemp digital infared thermometer. I am wondering if I am supposed to point it down, up, or sideways for an accurate reading? Depending on which direction I am pointing it, the temp could range by 20 degrees. So, I have no idea if the tank is warm enough in his basking spot. Also, am I missing anything with his lighting needs? I know how important it is. Please help! Thank you!

When using the heat gun.... I always point the gun downwards towards the basking spot at about the same distance as your basking light. 150W should be plenty. I use 50W Halogens about 8 inches from basking and get temps 95F to 98F in 75 gallon tanks. That is until recenty with Fall and cooler home temps. They have now dropped about 8F to 10F.

I also prefer to use a probed temperature gauge at basking. Especially becuase I live in Canada and the seasons drastically change the basking temps. As an adult beardie basking from 95F to 100F should be fine.

Thank you! I think I have the temps corrected now. My only other concern is if he is getting enough exposure to the UVB strip. It only goes across 3/4 of the tank and tends to hang out on the opposite side as the UVB. Does the strip need to go across the entire tank in order for him to get enough exposure? Thanks for your help.

No....I have two tanks where UVB goes right across...but I also have 2 that go about 3/4 the way. If they need the UVB they will go. 3/4 is perfect. It could be that your dragon is preferring the cooler side now as it is brumation time. All of mine are spending more time off the basking spot and in cooler areas now as well. Ah...the joy and worry of your first brumation. Cheers and best of luck with your new pet. They are truly wonderful.