First trip with new TPMS

[BB_TX]

Just returned from a 1841 mile trip with the TST TPMS. I have to say I do like it. Was comforting to be able to see the tire pressures and temps when ever I wanted. Lost contact to one sensor for about 30 miles. Did not restore contact until I stopped for lunch. But never lost contact afterward.
Somewhat surprised at the readings though. Tire pressures consistently rose 8 to 10 pounds above cold temps. No particular surprise there. But the temps barely rose above ambient air temp. Those on the shady side were at or no more than 2 degrees above the outside temp as showing on the truck display. And the tires on the sunny side rose no more than 12 to 14 degrees above that temp. And these were at highway speeds of 65-70, air temps of sometimes 100+, on some black asphalt highways, and sometimes running hours without stopping. In the past using a non-contact thermal gun seems I remember the surface temps of the tires ran more like 20 to 30 degrees above air temp. Did not take that device this trip to compare the readings.
So my question is, what exactly are the sensors reading for the temperatures. I feel sure they are not circulating air from inside the tire thru the sensor, are they?

[DQDick]

I had occasional loss of sensors with both of the TPMS that we've had. With TST I bought the signal booster and mounted it in the back window of the truck. Now no more problems. The sensors have to be just measuring the temp of the air in the valve stem, IMHO.

[Jolu]

Bill, I have a question. Do you have the regular sensors or do you have the flow through sensors?
Is one preferred over the other. I am about ready to order a set for the trailer.
Joe

[NCFischers]

The newer ones can accept an airchuck without removing the sensor. The batteries are also replaceable. I just converted from the other ones as my batteries were starting to go.

[BB_TX]

I have the TST 507 RV model. My sensors are not the flow thru. Just the regular ones. My batteries are replaceable. I think the flow thru and the others are the same price. I was just trying to minimize size/weight of the sensor. Not that I know they are any larger, just seemed they would have to be with the extra fitting on it.
Have never had any air loss in the 5 yrs the Michelins have been on so not having the flow thru is not a problem. I may add 2-3 pounds of air at the first of the season and am good the rest of the year.
.
I guess there is some natural circulation of air up the valve stem into the sensor for temp readings, but I can't imagine it being much without some method of forcing circulation. And would seem the valve stem would provide some cooling for that air. Oh well, curiosity killed the cat as the saying goes.

[DQDick]

Like John I have the flow thru and that makes it really nice since I mess with the pressure almost every single time we move and I don't have to take the sensors off to do it.