A bulk-pressure-ratio scan varies volume change, volume, and modulus together across three rows, checking that the product delta-P = K * delta-V / V stays constant row by row. The arithmetic is exact only for the stated pressures, volume changes, volumes, and modulus values in the ideal linear-elastic bulk model. Real materials add nonlinearity, hysteresis, geometry tolerances, temperature effects, load-cell/length calibration, finite precision, and measurement uncertainty.
Bulk pressure change follows modulus times volume-change ratio. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Bulk pressure follows modulus times volume-change ratio
Volume change 1 cubic meter over volume 6 cubic meters with modulus 12 Pa gives pressure change 2 Pa.
ΔP=KVΔV=12Pa⋅6m31m3=2Pa
Bulk pressure follows modulus times volume-change ratio
Volume change 2 cubic meters over volume 12 cubic meters with modulus 12 Pa gives pressure change 2 Pa.
ΔP=KVΔV=12Pa⋅12m32m3=2Pa
Bulk pressure follows modulus times volume-change ratio
Volume change 1 cubic meter over volume 8 cubic meters with modulus 16 Pa gives pressure change 2 Pa.