Hi, I have installed CS106 above 1.2 meter form Ground close to a run way. But the Barro reading is 1005 whereas the barro meter in the air plane reads as 996. Its a new CS106 calibrated / manufactured in 2010. Can anyone explain the difference.?. Thank you in advance.
Planes adjust their Altimeter settings to QFE, which is the pressure at the runway level so they know how high the are off the ground on runway approach. This article has a good explanation of QFE and QNH.
http://en.wikipedia.org/wiki/Atmospheric_pressure
Are you trying to supply runway pressure with the CS106?
Dave is onto the most likely cause of the discrepancy. A difference will be seen if the correction to sea level has been applied to the sensor output (as shown in our manuals, or offered by Shortcut).
If that has been in used this may explain the difference if the sensor if is at any significant height above sea level and that value has been entered in the correction equation. (It acts to increase the pressure reading to compensate for the height of the sensor).
Thanks Anrew & Dave. Its a great help