STS FM300 Compact Flow Transmitter
Compact industrial flow transmitter, nominal bore sizes to DN400, stated accuracy to 0.8%, temperature range −20 to +60°C; electric interfaces and matching sensing section depend on variant.
Source and engineering check
Official STS FM300 catalog and downloads · Manufacturer’s flow portfolio.
Ex safety: No blanket ATEX/IECEx rating is claimed for this series. Consult the ordered transducer, associated electronics and full system certificate before specifying hazardous-area applications.
FM300 compact meter architecture
The FM300 flow transmitter needs a compatible matched primary flow sensor: maximum DN400 family capability is not the transmitter’s independent measuring span. Confirm converter power, host outputs, process-media conductivity requirements and the full-meter accuracy conditions. Ambient operating temperature of the converter must be kept distinct from process fluid temperature and the flow tube’s mechanical pressure limit.
FM300 electronic converter — model-specific accuracy and conductivity
| Selection factor | Source-grounded product detail | Installed-system consequence |
|---|---|---|
| What the FM300 measures | STS markets FM300 as a compact electromagnetic flow transmitter / converter suitable with FM130/FM150 (up to DN400) and FM170 measuring tubes | This is not a standalone gas velocity sensor; the FM300 electronics need a compatible conductive-liquid inline flow tube. |
| Maker source discrepancy | Current STS flow-products page lists ‘accuracy up to 0.8%’; its February 2026 short datasheet headline says ‘±1%’ | These manufacturer figures are not presumed interchangeable. Get the ordered converter+flow-tube system uncertainty and test conditions. |
| Measurement medium and range | Manufacturer’s short datasheet requires minimum conductivity 20 µS/cm; electronics support tube full-scale velocities 0.4–10 m/s | Magnetic induction cannot directly measure dry gas, steam, oil or nonconductive liquids. Actual volume flow depends on DN and velocity. |
| Electrical and packaging | 10–30 VDC, ~1 W, IP67, 5-pin M12 connector; -20…+60°C ambient for electronics | Converter ambient limit is not the liquid process temperature or flow-tube PN pressure rating. |
| Output and accessories | Programmable digital pulses/alarms; optional 0/4–20 mA analog, display, IP68 housing and AISI304 option | Board’s ±0.2% measured-volume tolerance is not whole-system accuracy. Check exact analog burden and flow-tube pairing. |
Variant and approval conditions
Version 2026/02 documentation also states electronic board measurement tolerance ±0.2% of reading, and separately directs the user to a complete converter+sensor accuracy table. Neither makes the 0.8% web listing a universal statement. Source revision and exact order code remain open.
Original STS sources: STS current FM300 catalogue accuracy · STS FM300 short datasheet February 2026.