Pressure "zero" offset at Wykeham Farrance pneumatic system

[freequo]

Hello,
I was wondering if anyone here had a issue with the differences in pressure reading in the pneumatic system of triaxial apparatus?

I am havin problem with the adjustment of pressures in system. Pneumatic systems using rubber bladders is result in in negative pressure inside triaxial cell, producing negative pore water pressures in sample, although the pressure transducers have Ben "zero offset".

Anyone had similar issues/ experience?

[freequo]

So no one here had, or experienced or knows someone who had issues with air pressure triaxial system?