Thermal mass flowmeter

The ST75 flowmeter from Fluid Components International is now available in a remote mountable configuration for applications in hazardous areas or hard-to-reach locations. The ST75’s remote mount transmitter, which includes a full digital display, can be mounted up to 15 m away from its thermal mass flow sensor in the process piping and connected via two 0.50" FNPT cables.

The ST75 flowmeter is designed for line sizes from 6 to 51 mm and provides three outputs: the mass flow rate, totalised flow and media temperature. It features accuracy to ±2% of reading with ±0.5% repeatability and includes media temperature compensation to ensure performance in rugged environments. Its precision flow element has a no-moving parts design that employs platinum RTD sensors embedded in equal mass thermowells with microprocessor electronics calibrated to laboratory standards for a wide range of gases including natural gas, methane, nitrogen, CO₂, argon, all inert gases and compressed air.

The flowmeter operates over a flow range from 0.01 to 950 NCMH depending on line size. For variable process conditions, the ST75 is factory preset to a wide turndown range at 10:1 to 100:1. The fully scalable 4–20 mA and 0-10 V outputs are user assignable to flow rate and/or temperature and there is also a 0-1 kHz pulse output of total flow. The instrument can be ordered for input power with either 18 to 36 VDC or 85 to 265 VAC, with or without a built-in LCD digital display.

The ST75’s rugged sensing element features all welded 316 stainless steel construction with Hastelloy-C tips. It is enclosed in an IP66-rated package designed for hazardous area installations.