What Is a High-Precision Micro Gear Flow Meter?

A High-Precision Micro Gear Flow Meter is a positive displacement (PD) flow meter specifically designed for the accurate measurement of extremely low liquid flow rates. It can measure flows as low as 0.5 mL/min while maintaining an accuracy of up to ±0.2% FS (standard accuracy ±0.5% FS).

Unlike conventional flow meters that estimate flow based on velocity, a gear flow meter measures the actual volume of liquid passing through the meter by counting the precise rotation of internal gears. This makes it ideal for applications requiring high accuracy, excellent repeatability, and stable performance at very low flow rates.

Working Principle

A micro gear flow meter operates using the positive displacement principle.

As liquid enters the flow meter, the pressure difference between the inlet and outlet drives two precision gears to rotate. Each rotation displaces a fixed volume of liquid. By detecting the number of gear rotations, the flow meter accurately calculates both instantaneous flow rate and totalized volume.

Flow Rate = Displacement per Revolution × Number of Gear Rotations

Because the measurement is based on a fixed displacement rather than flow velocity, the flow meter provides highly stable and repeatable measurements.

Key Advantages

Ultra-High Measurement Accuracy

• Accuracy up to ±0.2% FS

• Standard accuracy ±0.5% FS

• Excellent repeatability

• Long-term measurement stability

Ideal for precision dosing, metering, and automated process control.

Extremely Low Flow Measurement

The flow meter is capable of measuring liquid flow rates as low as:

0.5 mL/min

This makes it suitable for:

• Precision dosing systems

• Laboratory instruments

• Medical equipment

• Chemical injection systems

• Semiconductor fluid delivery

• Adhesive dispensing equipment

Independent of Flow Profile

Unlike turbine or electromagnetic flow meters, a gear flow meter is largely unaffected by:

• Flow velocity

• Reynolds number

• Laminar or turbulent flow conditions

• Fluid density variations

This ensures reliable performance even under low-flow operating conditions.

Excellent Performance with High-Viscosity Liquids

As fluid viscosity increases, internal leakage between the gears decreases, resulting in improved measurement accuracy.

Typical media include:

• Lubricating oil

• Hydraulic oil

• Resin

• Adhesives

• Polymer solutions

• Ink

• Chemical liquids

• Fuel oils

Technical Specifications

Installation & Operating Considerations

Not Suitable for Fluids Containing Solid Particles

Precision gears require clean media for reliable operation.

Fluids containing:

• Metal particles

• Sand

• Powder

• Solid contaminants

may cause:

• Gear jamming

• Internal wear

• Reduced measurement accuracy

Installing a suitable filter upstream is strongly recommended.

Avoid Air or Gas Bubbles

Entrained air or gas may introduce measurement errors because gas occupies part of the displacement volume.

For best performance:

• Keep the pipeline completely filled with liquid.

• Prevent cavitation.

• Remove trapped air before operation.

Higher Viscosity Improves Accuracy

Higher-viscosity liquids produce less internal leakage, resulting in:

• Better accuracy

• Improved repeatability

• More stable long-term performance

Typical Applications

High-precision micro gear flow meters are widely used in:

• Precision dosing systems

• Chemical processing

• Pharmaceutical manufacturing

• Medical devices

• Laboratory equipment

• Lubrication systems

• Hydraulic systems

• Ink and coating equipment

• Resin and adhesive dispensing

• Semiconductor manufacturing

• Battery production

• Industrial automation

Why Choose a Gear Flow Meter?

Frequently Asked Questions (FAQ)

What liquids can a micro gear flow meter measure?

Micro gear flow meters are suitable for clean liquids such as lubricating oils, hydraulic oils, resins, adhesives, fuels, solvents, and many chemical liquids. They are not recommended for fluids containing large solid particles or fibrous materials.

Can it measure extremely low flow rates?

Yes. Depending on the model, the minimum measurable flow rate can be as low as 0.5 mL/min, making it ideal for precision liquid measurement and dosing applications.

What output signals are available?

Standard output options include:

• Pulse output

• 4–20 mA analog output

Digital communication interfaces can also be customized for specific applications.

Is it suitable for high-temperature applications?

The standard operating temperature range is -20°C to +80°C. With an optional cooling radiator, the maximum medium temperature can reach 200°C.

Conclusion

A High-Precision Micro Gear Flow Meter provides an ideal solution for precise low-flow liquid measurement. Based on the positive displacement principle, it offers exceptional accuracy, outstanding repeatability, and excellent performance with high-viscosity fluids.

Capable of measuring flow rates as low as 0.5 mL/min, it is widely used in industries such as chemical processing, pharmaceuticals, laboratories, medical devices, semiconductor manufacturing, battery production, and industrial automation. With multiple output options and customizable configurations, it is the preferred choice for high-accuracy fluid metering and process control.