Ultrasonic Gas Flow Meters
Daniel Measurement and Control
Houston, Texas
Measurement & Control
Presentation Outline
Introduction
Ultrasonic Flow Meter Fundamentals
Using and Buying Ultrasonic Flow Meters
Information and Diagnostic Functions
AGA-9 : An Ultrasonic Standard
Measurement & Control
Introduction
Measurement & Control
History of Ultrasonic Meters
z Liquid Meters Evolved First
z Gas Flow Meters Use Transit Time
Technique
z Commercially Introduced In the Mid-
80's
z High Accuracy Meters Introduced Into
the U.S. in 1993
Measurement & Control
Significance of Ultrasonic Meters
Why are they different?
Ultrasonic meters are the first "electronic"
measuring device proposed for custody
transfer ever!
Measurement & Control
Fundamentals of Ultrasonic
Flow Meters
Measurement & Control
Ultrasonic Transducer
Backing
Case
Material
Electrical Matching
Leads Piezoelectric Layer(s)
Disk
120 KHz In
24V Input Voltage Output
120 KHz Out
Measurement & Control
Transit Time Measurement
Intrinsically Safe Transducer Signal Loop
Pulser Receive Detector
120 kHz
Ultrasonic Signal
( Well Above Control Valve Interference at 60 kHz)
Clock
100 MHz Oscillator
Measurement & Control
Ultrasonic Flow Meter
Transit Time .004
X
Flow D
L
Transit Time .007 .003
Measurement & Control
Flow Equations
Any pair of transducers
L
tup = X
c - v(x/L)
Flow D
L
L
tdn =
c + v(x/L)
Measurement & Control
Flow Equations
Flow is determined from transit times
2
L (t1-t2)
v=
2x t1t2 v = flow velocity
c = speed of sound
L (t1+t2)
c= t1 = upstream transit time
2 t1t2 t2 = downstream transit time
Measurement & Control
Flow Velocity Measurement
Flowrate derived from velocity and area measurement
Flowrate = Velocity times Area
Measurement & Control
SeniorSonic Calculation
Multipath means multiple velocity measurements!
A
2
B L (t1 -t2 )
Vn = 2x (t1 t2 )
C
4
D Σ Wn Vn
Vavg = n=1
Multipath Meter
Measurement & Control
Geometric Weighting Factors
Fixed factors depend on geometry only!
A
Wa= 0.1382
B
Wb= 0.3618
C
Wc = 0.3618
D Wd= 0.1382
Multipath Meter
Measurement & Control
Multipath Flowrate Calculation
Steps to determining flowrate
Measure transit times for each path
Calculate velocity for each path
Calculate "average" velocity
Multiply velocity by meter body area
Measurement & Control
Flow Rate Calculations
z Flow Rate is Determined from Velocity
Measurement
z All Flow Information is Dependent on
Correct Transit Time Measurement
z Transit Time Measurements are
Performed by Electronic Means
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Signal Detection
Threshold Detection - Analog Technique
Voltage
Time (usec)
Measurement & Control
Signal Detection
Threshold Detection - Analog Technique
Voltage
Time (usec)
Measurement & Control
Ultrasonic Trace
Single transducer pair - low flow
300
250
200
150
100
50
-50
-100
Downstream Upstream
Measurement & Control
Ultrasonic Traces
Single transducer pair - high flow
250
200
150
100
50
-50
-100
-150
Downstream Upstream
Measurement & Control
Using and Selecting Ultrasonic
Flow Meters
Measurement & Control
Sizing Charts : Maximum Flowrate
Schedule 40, ANSI/ASME B36.10M
1200
8"
1000 10"
Flowrate (MMSCFD)
12"
800 16"
600
400
200
0
0 200 400 600 800 1000 1200
Pressure (psig)
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Range of Measurement
1000
100
Q (MMSCFD)
10
1 6" Maximum
6" Minimum
6" Extended
0.1
0 500 1000 1500 2000 2500 3000 3500
Pressure (PSI)
Measurement & Control
Types of Ultrasonic Meters
All use Transit Time Measurements
UltraTap Gas Flow Meter
Single-path, hot tapped devices
JuniorSonic Gas Flow Meter
Single- or dual-path spooled devices
SeniorSonic Gas Flow Meter
Multipath spooled devices
Intended for custody transfer
Measurement & Control
SeniorSonic Gas Flow Meter
z Highest Accuracy Available
z Custody Transfer Devices
z Multiple Paths Sample Velocity Profile
z Multiple Paths Provide Redundancy
z Precision Design and Manufacturing
Control
Measurement & Control
SeniorSonic Options
Transducer Configuration
Direct Mount
Extractable Under Pressure
Diagnostics and Logging
3405 Remote Frequency Interface
UFI Card
Measurement & Control
JuniorSonic Gas Flow Meter
Single or Dual Path Configuration
Spooled Body
Intended for Non-custody transfer
applications
Lower cost than the SeniorSonic
Ideal for new installations
Suitable for wet gas service
Measurement & Control
JuniorSonic Options
z Transducer Configuration
z Complete with spool piece
z Single or Dual Path configuration
z Extractable transducers available
z Diagnostics and Logging
z UFI Card
z 3405 Remote Frequency Interface
Measurement & Control
UltraTap Gas Flow Meter
Main Use is Balance in Existing Mainline
Transmission Systems
Popular for Use Near Compressors
Linear Devices
Pulsation Tolerant
Non-Custody Transfer Devices
Cost is Independent of Line Size
Measurement & Control
UltraTap Options
Installation Location
Surface
Underground or Buried
Ball Valve sizes 2" or 3"
Electronics options UFI or 34
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Benefits of Selecting Daniel
Ultrasonic Gas Flow Meters
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Complete Manufacturing
Capability
All meters are fully manufactured by Dan
No fabricators or "job shops" involved
Total quality control
Complete measurement solutions availa
Flow tubes and valves
Electronics
Measurement expertise
Measurement & Control
Manufactured to American
Standards
Manufactured and Engineered in the United
States
Conform to Underwriters Laboratory
standards
Local control over design and manufacturin
Easily interfaced to U.S. made flow
computers and electronics
Measurement & Control
Superior Customer Service
z Meter start-ups by qualified Daniel
personnel
z Ultrasonic flow meter specialists
z Full technical support from Houston
z 24-hour, toll free number for support
Measurement & Control
Technically Superior Design
SeniorSonic "patented" design
Over 15 years of design testing
No flow profile corrections needed
No "Matrix" manipulation of non-linear data
Intrinsically safe transducer design
Modbus interface is industry standard
No hidden or proprietary algorithms
Measurement & Control
Superior Electronics Design
z Mark II Electronics used on all models
z Immediate alarming of all possible problems
z Each path status is polled
z Each velocity calculation is shown
z No hidden path failures!
z UL certified and listed
z Intrinsically safe transducer design
z Advanced noise algorithms
Measurement & Control
Information and Diagnostic Functions
Measurement & Control
Flow Measurement Data
Normally Polled From Ultrasonic Meter
Flowrate
Accumulated Volumes
Alarm Status (Quality)
Reset Value
Flow Direction
Measurement & Control
Other Flow Measurement Data
Secondary Measurements
Gas Velocity
Individual Path Gas Velocities
Temperature
Pressure
Composition
Measurement & Control
Transit Time Data
Available for Alarming
Individual Transit Times
Statistical Information
Batch Statistics
Limits may be Set
Pulsations may be Detected
Low Flow Cut-offs
Measurement & Control
Common Diagnostic Information
Speed of Sound Measurements
Amplifier Gas (Signal Level)
Ultrasonic Noise Levels
Signal Quality
Signal Rejection Levels (%)
Data Distribution (Statistics)
Measurement & Control
Polling Ultrasonic Meter Data
Direct Digital Links to Meter
"Pulse" or Frequency Method
Allows Turbine Meter Replacement
Analog Proportional Output
Measurement & Control
Direct Digital Installation
P T
2500 2522 / 3330
Flow
RS 485
RS 232
Measurement & Control
Ultrasonic Custody Transfer
Standard
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AGA - 9
Measurement of Gas by Ultrasonic Meters
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AGA Report No. 9
Meter Requirements
Allows for Demonstrated Dry Calibration
Flow Conditioning is accomodated but not
required
Engineering Specifications are Included
Performance Envelope is Specified
Measurement & Control
AGA Report No. 9
Electronic Specifications
Electronic Alarms Must be Available
Diagnostic Information Must be Available
Flow Computer Computations are Specifie
Documentation is Specified
OIML R6 and D11 are Referenced
Dependent upon IEC Publications
Measurement & Control
