mass flow meter / for gas / compact / high-accuracy
ST51, ST51A EKOMAT GmbH & Co. KG



  • Technology:


  • Fluid:

    for gas

  • Other characteristics:

    compact, high-accuracy, 4-20 mA, insertion, rugged, IP67

  • Process pressure:

    150 psi, 500 psi

  • Process temperature:

    121 °C, 177 °C (250 °F)


The Model ST51 and ST51A are a compact, low cost solution for accurate, repeatable flow measurement of biogas, digester gas, landfill gas, methane and natural gas as well as air, compressed air or nitrogen. This insertion-style flow meter has no moving parts and is available in probe lengths for installation into pipe diameters from 2.5 inches to 24 inches [63 mm to 610 mm]. It is easily connected into the pipe via a 1/2 inch or 3/4 inch NPT compression fitting. ST51 uses constant power thermal dispersion drive technology, with a slightly heated sensor, which uniquely provides a subtle drying effect on the sensors that results in effective measurement in moist gas applications.

The ST51 Series electronics are housed in rugged, IP67 rated enclosure with dual conduit ports in either NPT or M20 threading. The instrument comes standard with dual 4-20 mA outputs and a 500 Hz pulse output. The model ST51A includes HART as well as a higher process temperature service range, NAMUR compliant 4-20 mA outputs and SIL compliance rating. The transmitter/electronics can be integrally mounted with the flow element (probe) or be remote mounted to best match your installation situation. The complete instrument carries global Ex agency approvals for Division l/Zone 1 installations.