1, CST simulations of the edge effects indicate a 1.6-2 mm extra offset/error
2, random error (to the offset): ~2%*Delte_x (1 MHz, Delta_X~5 mm)
3, error due to frequency: 1 mm
4, error due to temp.: ~2 mm level (22 degree -> 30 degree)
5, error due to the missing dummy pipe: 2 mm (x), 4 mm (y)
6, some issues related to VNA: impedance mismatch
7. Check with Peter about the frequency, temperature dependances, esp. the later one !!!
=> the mechanism of the temperature dependance is unknown!!
8. Check the error arisen from the Bergoz BB electronics at different temperature (urgent!)