Venturi-Structure Flowmeter Basics｜How to Choose Between FDM06-I and FDM08?

In pipeline flow measurement, the characteristics of the sensing element itself form the foundation of measurement accuracy, while the flow-field condition upstream of the measurement section determines whether these characteristics can be properly r

FDM06-I Venturi Thermal Mass Flow Meter combines a Venturi tube structure with the hot-wire measurement principle. Through the converging and diverging sections, the airflow becomes smoother and more stable before entering the sensing zone, allowing the hot-wire element to operate under a more uniform flow field and improving measurement linearity and repeatability. The FDM06-I is equipped with a 2”LCD display that can show instantaneous and cumulative flow, and it supports multiple outputs (analog / digital). Models are available for pipe diameters from DN15 to DN100, making it suitable for applications that require stable airflow monitoring, pipeline flow statistics, and consumption tracking.

FDM08 Venturi Inline Type Air Flow Transmitter, which also adopts a Venturi structure, is more suitable for pipeline sections in compressed air systems where the gas contains higher moisture content. When site conditions involve moisture or condensation risks, selecting a Venturi pipeline-type measurement architecture allows flow monitoring to better match actual operating conditions. From an engineering selection perspective, it can be understood as using the same Venturi-based flow stabilization concept but addressing different pipeline conditions and application scenarios.