Variables:
A	Cross-sectional Area of the Venturi throat
Ad	Cross-sectional Area of the pipe
C	Capacitance
Cd	Discharge coefficient
c	Sensitivity coefficients
D	Diameter of the Venturi throat
d	Diameter of the pipe or Venturi inlet
dp	Differential pressure
dt	Time interval between two detection of the dual-ECT
e	Error term
f	Detection frequency or function
L	Distance between the two planes of dual-ECT
M	Number of simulation tests
n	Total number or serial number
p	Pressure or level of confidence
Q	Volume flowrate
Qtot	Total Volume flowrate
Qth	Estimated total flowrate of the dual-ECT
Qtp	Indicated gas flowrate of the Venturi
s	Standard deviation
T	Temperature
t	time
U	Expanded uncertainty
u	Standard uncertainty
urel	Relative standard uncertainty
uc	Combined uncertainty
X	Lockhart-Martinelli Parameter
x	Independent variable
Y	The reciprocal of X
y	Measurand or dependent variable
Symbols:
β	Diameter ratio or regression coefficients
ε	Expansion factor
Σ	Covariance Matrix
σ2	Residual Variance
ρ	Density
τ	Time delay
φ	Over-reading
Abbreviations:
Cap	Capacitance
CC	Cross-Correlation
DP	Differential Pressure
ECT	Electrical Capacitance Tomography
ERT	Electrical Resistance Tomography
Eq.	Equation
Fig.	Figure
GUM	Guide to the expression of Uncertainty in Measurement
L-M	Lockhart-Martinelli Parameter
LVF	Liquid Volume Fraction
MAE	Mean Absolute Error
MAPE	Mean Absolute Percentage Error
MAPU	Mean Absolute Percentage Uncertainty
MAU	Mean Absolute Uncertainty
MCM	Monte Carlo Method
MPFM	Multiphase Flow Meter
PDF	Probability Density Function
Std.	standard
UA	Uncertainty Analysis
Subscripts:
avg	average
g	gas
l	liquid
rel	relative
0	Estimated value