Why is a turbine flowmeter specifically used for measuring low-viscosity, clean media?

The fundamental reason why turbine flowmeters are designed specifically for low‑viscosity, clean media is that they are a type of precision “velocity” flowmeter. Their core working principle and precision mechanical structure determine that they can only maintain high accuracy and reliability in an ideal operating environment.

High cleanliness: 

The presence of tiny particles can invade and wear out the bearings, or fibrous impurities may entangle the impeller.

• Permanent accuracy degradation that is irreversible
• Increased rotational resistance, causing negative errors
• In severe cases, the impeller may seize, rendering the meter completely inoperative

Low viscosity: 

Fluid viscosity affects the Reynolds number; high viscosity disrupts the ideal flow regime and introduces excessive resistance.

• Non‑linear changes in the meter coefficient, making accuracy unguaranteed
• Unable to start at low flow rates or exhibits significant errors, with poor linearity