you failed to mention the sensor brand.
I know when I put mine on (Pressure Pro) and had the rig weighted by Aweigh we go (RVSafety.com) they told me the PP's are usually within 1 pound of their lab calibrated stick gauges..... Alas. not all tire gauges are that close.
Suggestion, if you have not already gotten wheel weights for your Rig.. You might want to check with those folks. the price was not much more than two trips across a segmented fixed scale (What you need to get wheel weights) and the service was excellent.