Ultrasonic Flow Meter Calculator

Calculation Mode:

Calculate Flow Rate Diagnostic Check

Meter Configuration

Meter Size

Number of Paths

Path Configuration

Meter Body I.D.

Internal diameter of meter spool piece

Operating Conditions

Flowing Pressure

psig

Flowing Temperature

°F

Avg Transit Time Upstream

μs

t_up — against flow direction

Avg Transit Time Downstream

μs

t_down — with flow direction

Gas Properties

Gas Specific Gravity (Air=1.0)

Natural gas: 0.55–0.70, Methane: 0.554

Compressibility Factor (Z)

Typical: 0.85–1.00 for natural gas

Isentropic Exponent (k)

Natural gas: 1.27–1.31, Methane: 1.31

Speed of Sound from GC

ft/s

Optional — from gas chromatograph for SOS validation

Meter Data

Meter Size

Number of Paths

Measured Speed of Sound

ft/s

Average SOS reported by USM

Speed of Sound from GC

ft/s

Calculated from gas chromatograph analysis

Diagnostic Parameters

Profile Factor

Ratio of avg to center path velocity (typical 0.95–1.05)

Symmetry

Flow profile symmetry factor (ideal = 0)

Crossflow

Cross-pipe velocity component (<2% preferred)

Turbulence

Turbulence intensity (<5% typical)

Signal-to-Noise Ratio

Average SNR across all paths (>30 dB preferred)

Transit-Time Flow Equation

V = (L / 2cosθ) × (t_up − t_down) / (t_up × t_down)

V = Average gas velocity along acoustic path

L = Acoustic path length

θ = Path angle from pipe axis

t_up, t_down = Transit times upstream / downstream

Standards & References

AGA Report No. 9
Measurement of Gas by Multipath Ultrasonic Meters
AGA Report No. 10
Speed of Sound in Natural Gas
ISO 17089
Ultrasonic Meters for Gas (Parts 1 & 2)

Frequently Asked Questions

What is AGA Report No. 9?

AGA Report No. 9 is the industry standard for measurement of gas by multipath ultrasonic meters used in natural gas custody transfer.

What does this ultrasonic meter calculator provide?

It performs AGA 9 ultrasonic flow meter calculations for natural gas custody transfer measurement with diagnostic validation.

What is diagnostic validation in ultrasonic metering?

Diagnostic validation uses parameters like speed of sound, path velocity ratios, and signal quality to verify the ultrasonic meter is operating correctly.

Meter Configuration

Operating Conditions

Gas Properties

Meter Data

Diagnostic Parameters

Flow Measurement Results

SOS Validation

Diagnostic Results

Transit-Time Flow Equation

Standards & References

Frequently Asked Questions

Ultrasonic Flow Meter Calculator

Meter Configuration

Operating Conditions

Gas Properties

Meter Data

Diagnostic Parameters

Flow Measurement Results

SOS Validation

Diagnostic Results

Transit-Time Flow Equation

Standards & References

Frequently Asked Questions

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