Afternoon - just settling in the Tempest and noting the pressure is different compared to my airs (i have 3 airs due to humidity failures with early units) - the airs also approx match my Vue:
Airs - 997,7, 999.1, 998.6
Vue - 998.7
Tempest - 1001.4
https://tempestwx.com/station/26848/grid
The heights/locations are all set the same, so just wondering if the variation is within the known boundaries?
Andy
if you go to settings/station, what is the elevation listed (I noticed on https://en-gb.topographic-map.com/maps/b9/England/ there is a pretty sharp drop in elevation on the map). If you add to that the height above ground from your tempest, does the total height above sealevel match the one used by Airs or Vue?
It could be that your Tempest us waiting on a calibration.
btw looking at UK weather forecast map - Met Office it looks like the tempest is more close to the expected value than the other two.
Edit, then again at UK weather forecast map - Met Office it looks more like 997, o well…perhaps check again at some other time.
more edit… wait, your station is reporting 997 at the moment, so it should be ok 
Thanks for looking - the 997 is from the old hub and an air, so i guess the tempest is waiting a calibration.
It would be good to get a message when it calibrates, just so the user knows, the rain is also way off at the moment (under reporting) on the Tempest…
Andy
Just to add - in reply to @sunny in terms of elevation - they are both at 15.1m which it looks like the app now gets from the location of the station on set up. The airs are on the ground and tempest is approx 3m up on a pole. It was higher but when winds got over 20mph i was getting false rain readings.
Did you look up the WF specs on the pressure sensors for the various devices ? That would answer your question. FWIW my field test Tempest matches my 2009 VP2 exactly (like amazingly exactly).