Error sources

Affected bubble lengths

Type of error

Uncertainty [mm]

Uncertainty of measuring x₁₂

All

Systematic

0.05

Changes of x₁₂ due to thermal expansion (5 K difference)

All

Systematic

0.01

Other changes of x₁₂

All

Both

Small

Uncertainty in c due to temperature measurement uncertainty (±1 K)

All

Systematic

0.26

Uncertainty in c due to temperature variations (±0.5 K)

All

Random

0.13

Uncertainty of measuring T₀ from Equation (3)

All

Systematic

0.01

Uncertainty of detecting T by the cross-correlation

All

Random

0.09

Pulse shape change due to interference with multiple reflections of the pulse from the opposite TDX

Few

Random

0.36 - 0.95

Pulse shape change due to the shadowing effect of other bubbles

Few

Random

0.36 - 0.72

Incorrect pairing due to overlapping

Few

Systematic

1 - 5