Download Proposal

TUSTP 2003
DOE Project:
StarCut Differential Dielectric
Sensor — Experiments and Modeling
By
Dong Xiang
May 20, 2003
Topics





Introduction
Fundamentals of Microwave Measurements
Measurement Methods of Permittivity
Proposed Solution
Future Plans
Introduction
 StarCut is ChevronTexaco’s meter for
continuous measurement of multiphase
fluid composition
 Microwave signal is used to measure
dielectric properties of the fluids
 At present, no analytical model is
available for StarCut
Topics
Fundamentals of Microwave Measurements
 Waveguide
 Microwave Characterization
 S-Parameter
Sensor Cell of StarCut
Fluid
Transmitting Antenna
Receiving Antenna
Waveguide
 Waveguide is used for efficient transfer of
microwave signals from one point to another
 In StarCut, rectangular waveguide is used
Microwave Characterization
Sample
Incident Wave
Reflected Wave
Transmitted Wave
Why Use S-Parameter?
It is very hard to measure total voltage and
current at device ports
S-Parameter is relatively easy to obtain at
high frequency
S-Parameter is related to familiar
measurements (gain, loss, reflection
coefficient)
S-Parameter Measurement
Topics
Measurement Methods of Permittivity
 Transmission Line Method
 Reflection/Transmission Method
 Amplitude Attenuation + Phase
Shift
 S-Parameter
 Transmission Line Equation Method
 Cavity Resonator Method
 Full Wave Analysis Method
 Perturbation Theory Method
Transmission Line Method
Waveguide structure is modeled as
transmission line
Transmission line parameters are
measured to determine permittivity
Amplitude Attenuation and
Phase Shift
Lookup Table Method (Hatton,Texaco,
1989)
 This patent is the theoretical
foundation of StarCut currently used
in North Campus
 Attenuation + phase shift + Database
(lookup table)
Amplitude Attenuation and
Phase Shift
Analytical method (Kraszewski, 1990)
 Measurement has to be done twice
using different thickness of sample
 It is difficult for dynamic measurement
 No hole-effect consideration
S-Parameter Method
S-Parameter is measured to determine
permittivity (Marrelli, ChevronTexaco,
1997)
No hole-effect consideration
Transmission Line Equation
Method
Transmission line equation and boundary
condition are used to determine
permittivity
 This is the theoretical foundation of
Huang’s Thesis (1997)
 Polynomial fitting for hole-effect
Huang’s Model
Section 2
Section 1
Section 3
Cavity Resonator Method
Resonance frequency is measured to
determine permittivity
Network analyzer is used to get resonance
frequency
Advantage: hole-effect can be considered
Only valid for low-loss material, not useful
for multiphase flow measurement
Full Wave Method
Resonance frequency is determined by
electromagnetic equation and boundary
condition
Advantage: hole-effect can be easily
calculated
This is the theoretical foundation of
Janezic, NIST (Colorado, 1999)
Perturbation Theory
Resonance frequency is determined using
perturbation theory for material in cavity
resonator
Advantage: hole-effect can be calculated
Disadvantage: too many assumptions
affect the measurement accuracy
Topics
 Proposed Solution:
 Transmission Line Method
Solution: Model
Resonator method is not good for our
case
Reason: multiphase fluid has high loss
Transmission line method is considered
Future Plans
 Develop model for StarCut, minimize
hole-effect
 Hardware Improvement of StarCut
 Use StarCut to measure other parameters
in multiphase flow
Thank You!