The Null Method

The Null Method for soil pressure measurement is based on the premise that:

"If sensor deflection is eliminated then the pressure required to eliminate that deflection is the pressure applied by the soil/particulate media."

It turns out that the premise is correct, the result is that the system is valid for different soils, different conditions, load and unload response. See the plots below.

This means:  No more sensor specific or soil specific calibrations ! No more parasitic hysteresis due to unloading !

The same concept works at a soil - structural boundary, or within a soil mass.