Turbine flowmeters measure volumetric flow by converting fluid energy into rotor rotation. Key technical parameters define their performance and application limits. The K-factor is pulses per unit volume, usually pulses/liter or pulses/gallon. It depends on meter size, rotor design, and fluid viscosity. Accuracy is typically +/-0.5% to +/-1.0% of reading, with repeatability of +/-0.1%. Linearity shows how K-factor varies across flow range; a good meter maintains stable linearity after calibration.

Flow range and turndown ratio determine usable span. Common turndown is 10:1 or 20:1, while low-flow performance is limited by bearing friction. Pressure rating ranges from 1.6 MPa to 42 MPa or higher, depending on body material and connection. Temperature ratings vary from -20C to 150C for standard models, with high-temperature versions reaching 200C or more.

Materials include 304/316 stainless steel, brass, or aluminum. Bearings may be tungsten carbide, ceramic, or sapphire for wear resistance. Output signals include pulse, 4-20 mA, HART, and Modbus. Power supply is often 24 VDC or loop-powered. Pressure loss is moderate but must be checked. Viscosity affects accuracy; high viscosity reduces rotor speed and may require correction.

Installation requires straight pipe: often 10D upstream and 5D downstream. A filter protects the rotor from particles. The meter should remain full and free of air. Regular calibration ensures reliable data in oil, water, chemicals, and fuel applications.