Instruments that measure fluid flow are collectively called flow meter. Flow meter are one of the important instruments in industrial measurement. With the development of industrial production, the accuracy requirements for flow measurement are getting higher and higher, and flow measurement technology is changing with each passing day. In order to adapt to a variety of uses, various types of flow meters have come out.

In fully automatic chromatography system configurations, the most commonly used flow meters are mass flow meters and electromagnetic flow meters.

1. Mass flow meter

When fluid flows in a rotating pipe, the pipe wall will generate a force. This was discovered by Coriolis in 1832 when he was studying turbines, and is referred to as the Coriolis force. The mass flow meter is based on the KOCI force. There are two parallel oil tubes inside the sensor, with a drive coil in the center and induction coils at both ends. When the provided excitation voltage is added to the drive coil, the oscillation tube vibrates in a reciprocating period. The fluid medium in the industrial process passes through the oscillation tube of the sensor, causing a Coriolis force effect on the oscillation tube, twisting the two oscillation tubes. The induction coils installed at both ends of the oscillation tube have different phases. The computer interprets the mass flow rate through the oscillation tube. When different media pass through the sensor, due to the different main vibration frequencies of the vibrating tube, the density of the medium will be interpreted accordingly. The mass flow meter can directly measure the mass flow rate of the medium passing through the flow meter, or it can also measure the density of the medium and indirectly measure the temperature of the medium.

Advantages: Can measure the flow rate of various solutions including pure water. The mass flow meter has excellent performance and reliable measurement. Used for original trade settlement, custody transfer and material balance of each production unit. The selection and application quality of mass flow meters are conducive to energy conservation, consumption reduction and emission reduction of resources, and are conducive to the optimization of production operations, which are directly related to the benefits of the enterprise.

Mass flow meters can measure a variety of materials, so they can be used to measure flow rates in many industries. The companies we use are quite convenient and will not be affected by many factors.

When measuring, it can achieve high accuracy, fully guarantee the measurement effect, and provide many favorable conditions for the production of enterprises. Therefore, using it can fully ensure that the materials in production are well controlled, and the quality of the products produced will only be better.

Disadvantages: large size, weak shock resistance, and installed directly on the pump (will affect accuracy).

2. Electromagnetic flow meter

Electromagnetic flow meter use conductors to generate induced electromotive force when moving in a magnetic field. The induced electromotive force is generated by measuring the electromotive force in proportion to the flow rate, reflecting the principle of pipeline flow. The measurement accuracy and sensitivity are very high. The maximum pipe diameter that can be measured is up to 2 meters. The pressure loss is very small, but it is not suitable for media with low conductivity.

Advantages: small size, good shock resistance, can be installed directly behind the water pump.

Disadvantages: When the liquid conductivity is less than 5 S/CM, it will affect the detection accuracy.