Ultra Low-Micro Liquid Flow Measurement

Ultra Low-Micro Liquid Flow Measurement

Ultra Low-Micro Liquid Flow Measurement is widely used in many industries, the smaller the flow, the more difficult the measurement. What kind of flow meter must be used to measure the liquid with a small flow rate?

There are many kinds of common flowmeters suitable for measuring tiny, such as differential pressure type, float type, positive displacement type, etc. Some of these flowmeters are suitable for measuring both large and small flows, while others are specially designed for measuring small flows.

Challenges of micro liquid flow measurement

The measurement of tiny flow is widely used in many industries. The smaller the flow, the harder it is to measure. This is also a big challenge for instrument manufacturers.

In the selection of flowmeters for measuring small flows, there are the following points for attention.

  1. Instrument performance. It refers to the accuracy, repeatability, linearity, turndown ratio, pressure loss, initial flow rate, output signal and response time of the instrument. When selecting a flow meter, the above indicators should be carefully analyzed and compared.
  2. Economic factors. Refers to the purchase fee, installation fee, maintenance fee, calibration fee and spare parts. It is also affected by the performance, reliability, and life of the flowmeter.
  3. Installation conditions. Refers to the fluid flow direction, pipeline direction, upstream and downstream straight pipeline length, pipe diameter, spatial position and pipe fittings, etc.
  4. Fluid properties. Mainly refers to pressure, temperature, viscosity, etc.
  5. Accuracy grade and function. Choose the accuracy level of the instrument according to the measurement requirements and usage occasions to achieve economical results.

Types of micro liquid flow meters

Today, there are countless types of small flow meters, as many as dozens. The measurement medium also widely includes liquid (liquid), gas, oil, viscous medium, corrosive medium, etc. It can be measured with a small flow meter. There are still many small flowmeters for liquid measurement, some of which not only have high precision but also high stability.

The Coriolis mass flowmeter is a device that uses the principle of Coriolis force proportional to the mass flow generated when the fluid flows in the vibrating pipeline to directly measure the mass flow.

Coriolis flow meters are the only technology that can measure mass flow directly and independently of fluid composition, and can also measure density. By calculating the mass due to the vibrational changes caused by the flow, it is then converted to flow and density. (For those who are interested in how Coriolis works, click here.)

Coriolis is ideal for repeatable high precision mass flow and density measurements. Even when liquid composition is unknown or changes.

Another advantage of Coriolis technology is its high compatibility. A Coriolis meter can be used for both liquids and gases (including corrosive liquids/gases). Note that the medium cannot have too high a viscosity. These features make Coriolis meters perfect for high precision low flow liquid applications.


  1. Fluids with changing or unknown composition
  2. Corrosive fluid
  3. High pressure
  4. High precision
  5. Measure and control liquid and gas with a single instrument


  1. Not suitable for high viscosity liquid
  2. The cost of Coriolis mass flowmeter will be relatively high.

Ultrasonic liquid flowmeters work on the principle of velocity difference. Consisting of a pair of sensors clamped to the pipe, it uses the Doppler effect to determine fluid velocity. Ultrasound is then sent through the fluid in the pipe. The sensor calculates the liquid flow rate based on the change in signal frequency.

Ultrasonic flow meters are ideal for applications requiring a non-invasive method of flow measurement, such as wastewater treatment.

Because the instrument and the fluid flow are not in a horizontal line. These instruments can therefore measure extremely aggressive liquids. And there is no pressure drop requirement. And maintenance costs are often lower. Its main disadvantage is that the measurement accuracy is often low. And they are especially susceptible to process vibrations and external environmental disturbances.


  1. Non-invasive measurement
  2. Low pressure
  3. Highly corrosive liquid
  4. Liquid with large particles


  1. High precision process
  2. Processes sensitive to vibration

The turbine flowmeter is a velocity flowmeter. Its working principle is based on the fact that the rotational angular velocity of the impeller placed in the fluid is proportional to the fluid flow velocity. The flow velocity of the measured fluid is obtained by measuring the rotational angular velocity of the impeller.

With the help of precision ball bearings, the turbine flowmeter can achieve high-precision measurement at low flow rates. And has a very fast response time (even as low as 3 milliseconds). They are also suitable for wide flow and operating temperature ranges.

These features make turbo liquid flow meters a good choice for measuring fuel and coolant flow in engines and engine development. However, it is not recommended to use a turbine flowmeter for flowing polluted or corrosive liquids. Interruption of the measurement due to possible damage to the bearing.


  1. Fast response time
  2. Extreme temperature
  3. High precision


  1. Liquid with large particles
  2. Corrosive liquid
  3. Liquid with unknown composition

New Product – GF Series Gear Flow Meter

The original design intention of GF Series Gear Flow Meter is for industrial micro flow measurement. The smallest model, GF02, can measure tiny flows of 0.6-50 L/H.

The micro flowmeter is a volumetric flow transmitter based on a gear flow transmitter.

Inside the metering chamber are two circular gears. The gear meshes and rotates with the flow of the medium. Under the action of fluid flow, a pressure difference is formed at both ends of the meter inlet and outlet. No power is required, and a pair of gears rotate freely. The cavity between its gears is filled with liquid, which is discharged as it rotates. Measuring the number of rotations of the gear can know the liquid flowing through the instrument, and the flow of the liquid can be used for micro flow measurement.

More about GF Series Gear Flow Meter Specifications.

Technical Advantages of Gear Flow Meter Measuring Micro Liquid Flow

  • The greater the viscosity of the medium, the smaller the leakage from the gap between the gear and the metering space. Therefore, the greater the viscosity of the measured medium, the smaller the leakage error. It is more beneficial to the measurement.
  • Small size, light weight, low vibration and noise during operation.
  • Fluids with viscosities up to 10000Pa.s can be measured;
  • The measurement accuracy is 0.5 and 0.2. Wide measurement range up to 100:1
  • There are general type, high pressure type (40mPa), food type and so on.
  • Standard fluids operation temperature : -15-80°C, Special request for fluids temperature :-196°C~200°C;
  • Suitable for small flow measurement of various cleaning liquids.
  • No straight runs are required.
  • Suitable for pulsating fluid measurements.
  • It can be used for quantitative addition of micro amount and short time

Read more about: Flowmeters for Cryogenic Fluids Flow Measurement

micro liquid flow meter- drop water can be measured


Measurable medium:

  • Resin, glue measurement,
  • Hydraulic oil, lubricating oil, grease measurement,
  • fuel oil measurement,
  • Inks, bitumen measurement,
  • Liquid nitrogen, freezing liquid, solvent measurement,
  • Edible oil, fish oil and food filling measurement,
  • Chemical and anti-corrosion requirements fluid measurement,
  • Dye Measurements
  • Fluid Quantitative Control System

More Featured Liquid Flow Meters

Sino-Inst, Manufacturer for GF Series Gear Flow Meter for ultra low – micro liquid flow measurement. For example crude oil flow meter, diesel flow meter, gasoline flow meter.

GF Series Gear Flow Meter is a new type of volumetric flow transmitter, used for precise continuous or intermittent measurement of liquid flow or instantaneous flow in pipelines.

GF Series Gear Flow Meter is especially suitable for flow measurement of heavy oil, polyvinyl alcohol, resin and other media with high viscosity. (Fluid with viscosity up to 10000Pa.s can be measured).

GF Series Gear Flow Meter is small in size, light in weight, low in vibration and noise and stable in operation. It can also be used to measure small flow rates with small pipe diameters. The initial flow rate is small and the range ratio is wide. It is suitable for measuring compliance with large changes. liquid flow.

Sino-Inst’s GF Series Gear Flow Meter for Micro liquid flow, made in China, Having good Quality, With better price. Our flow measurement instruments are widely used in China, India, Pakistan, the US, and other countries.

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