Oil & gas S
EX~
ussex based Ex~i Flow Measurement’s flagship product, the SFC3000 flow computer, is the evolution of 45-years’ work, creating what Ex~I Flow Measurement believes is the best gas flow measurement computer available – backed with the best technical support.
The first generation SFC3000 was released in 2007, but before that, members of the same design team were also involved with several other predecessors of flow computer models, which in one way or another, form part of its extended family history.
Hardware and software have evolved a great deal over the decades, a quick example of this being the computational time per calculation, which has dropped from 10 seconds, down to just 100ms!
In this article, we look back through time to see how far measurement and data processing technology has evolved to lay the foundations of the SFC3000 Flow Computer.
EVOLUTION OF GAS FLOW MEASUREMENT TECHNOLOGY: PERFORMANCE MILESTONES FROM 1980 TO 2009
Gas flow measurement instruments have evolved significantly over the past three decades, driven by advances in sensor technology, digital processing, and system integration. This application note outlines key technology milestones between 1980 and 2009, highlighting how improvements in accuracy, response time, processing capability, memory, connectivity, and user interfaces have enhanced the performance and reliability of modern gas flow meters and mass flow controllers.
INTRODUCTION
Accurate and stable gas flow measurement is critical in applications ranging from semiconductor manufacturing and industrial process control to laboratory research and gas distribution. Early gas flow instruments relied heavily on mechanical and analogue techniques, limiting accuracy, repeatability, and integration capability. Beginning in the early 1980s, digital electronics increasingly enabled advanced compensation, calibration, and communication features. By 2009, gas flow instruments had become software-defined, networked devices with high precision, fast dynamic response, and extensive diagnostic capability.
26 Application Impact Suitable for indication and basic monitoring
Limited repeatability and automation capability
2.2 1982: INTRODUCTION OF DIGITAL COMPENSATION Measurement Performance
Early digital linearization of thermal sensors
Measurement Performance Multi-point digital calibration Accuracy of ±1% or better achievable Gas-specific correction factors supported Signal Processing
Sampling rates in the kHz range Digital filtering improves stability
March 2026 Instrumentation Monthly
By Daniel Goodwin, managing director, EX~i Flow Measurement TECHNOLOGY MILESTONES
Accuracy improved to ±1–3%
2.1 1980: PREDOMINANTLY ANALOGUE GAS FLOW INSTRUMENTS Measurement Performance
Flow sensing based on mechanical elements or early thermal sensors Typical accuracy: ±2–5% of reading Limited temperature and pressure compensation Signal Processing
Analogue signal conditioning
Slow response times, unsuitable for fast control loops
Electronics and Memory Minimal microprocessor usage
Calibration adjustments performed mechanically
No digital storage of calibration data Interfaces and Displays
Analogue outputs (4–20 mA, 0–10 V)
Analogue gauges or basic LED numeric displays
Basic temperature compensation implemented
Signal Processing Digital averaging reduces noise
Improved response time for control applications
Electronics and Memory 8-bit microcontrollers at 5–8 MHz EPROM-based storage of calibration curves Interfaces and Displays Continued analogue outputs
RS-232 introduced on select laboratory instruments
Character LCDs display flow and setpoint Application Impact Improved repeatability
Early adoption in laboratory mass flow controllers
2.3 1993: DIGITALLY CALIBRATED GAS FLOW MEASUREMENT
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