ST100A Thermal Mass Gas Flow Meters

The ST100A Series from Fluid Components International (FCI) represents the next generation of thermal dispersion gas flow measurement. Designed for the most demanding industrial process and plant applications, the ST100A is a comprehensive, triple-variable communications center for your piping system. By measuring mass flow, temperature, and pressure simultaneously, the ST100A eliminates the need for multiple sensors and complex flow computers, streamlining process automation and reducing hardware overhead.

Advanced Thermal Dispersion Technology

At the core of the ST100A is FCI’s signature thermal dispersion technology. This method provides direct mass flow measurement without the need for additional pressure or temperature compensation. Because it has no moving parts to foul or clog, it is the ideal solution for “dirty” gas applications—such as wastewater aeration, flare gas, and biogases—where traditional orifice plates or turbine meters would fail or require constant maintenance.

The ST100A features a wide 100:1 turndown ratio and is capable of measuring flow rates from as low as 0.25 SFPS to as high as 1000 SFPS ($0.07$ to $305$ NMPS). This wide dynamic range allows the meter to handle both low-flow leak detection and high-velocity peak process demands with the same high level of precision.

Unmatched Communication Flexibility

The ST100A was engineered to be the most “connected” thermal meter on the market. Whether your facility relies on traditional analog signals or the latest digital bus protocols, the ST100A integrates seamlessly into your DCS or PLC. It features dual 4-20 mA outputs that are user-assignable to any of the measured variables, along with a 0-1 kHz pulse output for totalization.

For digital integration, the ST100A supports:

• HART (Version 7)

• Foundation Fieldbus (H1)

• PROFIBUS PA

• Modbus RS-485

Performance and Environmental Specifications

Mechanical and Material Configurations

The ST100A Series is available with multiple sensor styles to match specific application needs. The FPC-style provides a fast-response, protected sensor for clean gases, while the S-style is a rugged, all-welded design built for extreme durability in heavy industrial environments.

Data Logging and Calibration

Every ST100A comes with a massive on-board memory capable of storing up to 21 million readings, which is invaluable for regulatory compliance, emissions reporting, and troubleshooting process upsets. Furthermore, the meter supports up to five unique calibration groups. This allows a single meter to accurately measure different gas mixtures or account for varying process pressures without needing to be physically swapped or recalibrated in the field.

ST100A Series Model Summary