Originally Posted by sokhapkin
Internal sensor is inside the tire. Screw on stem sensor is few inches outside the tire. That makes a big difference in the inside tire temperature sensing.
As for basic physics, any temperature sensor measures its own temperature. The temperature of inside tire sensor is much closer to inside tire temperature than temperature of screw on stem sensor.
I would also question the 'absolute' accuracy of temperature and maybe even pressure.
Absolute accuracy isn't necessary to provide value. The reality is that you can see pressure and temperature changes. When one tire is 20 degrees hotter than another you can recognize a problem, when you see pressure dropping compared to another.....
We've seen both situations. As suggested we had a tow vehicle without pressure sensing and installed the two extra sensors on the tow vehicle.
Our new tow vehicle has sensors inside the tires
but only reports a fault and does not monitor temperature, they're not as good as the stem sensors we had.