Working Principle of Target Flow Meter
When the medium flows in the measuring tube, the pressure difference is generated when its own kinetic energy passes through the baffle (target). A force is applied to the baffle. The magnitude of the force is proportional to the square of the medium flow rate. The mathematical expression is as follows:
F=CdA ρ·v²/2
Where:
F——Force applied to the baffle (kg)
A——Axial projection area of the baffle on the measuring tube (mm²)
v——Average flow rate of the medium in the measuring tube (m/s)
Cd——Object resistance coefficient
ρ——Density of the medium under working conditions (kg/m³)
The force F applied to the baffle (target) is transmitted to the sensor through the rigidly connected transmission member (measuring rod), and the sensor generates a voltage signal output: V=KF
Where:
V——Voltage output by the sensor (mV),
K——proportional constant,
F——force exerted on the flow blocker (target) (kg)
Thus, the corresponding instantaneous flow and cumulative total can be obtained through AD conversion and computer processing
Advantages and Disadvantages of Target Flow Meter
Advantages:
- The display adopts English display with backlight, which can display multiple parameters at the same time and support data display
- Can realize one-way or two-way measurement;
- Can realize alarm output function;
- Can realize quantitative control function
- There are many installation methods to choose from, such as online insertion, with low installation cost;
- With integrated temperature and pressure compensation, direct output of quality or standard;
- With optional small signal cut In addition, nonlinear correction, and filtering time can be selected;
- It can accurately measure the gas and liquid flow under various working conditions of normal temperature, high temperature 500 degrees, and low temperature -200 degrees;
- The measurement is accurate, and the accuracy can reach 0.5%.
- The repeatability is good, generally 0.05-0.08%, and the measurement is fast.
- The pressure loss is small, only about 1/2△P of the standard orifice plate.
- It has strong anti-interference and anti-impurity capabilities.
- The flow range can be changed by replacing the flow blocker (target plate) according to actual needs.
- It is simple and convenient to install and extremely easy to maintain.
- A variety of output forms can transmit various parameters remotely.
- It has strong vibration resistance and can measure pulsating flow within a certain range.
Disadvantages:
- Because the target plate and target rod of the target flow meter have their own weight, the zero point must be reset after installation;
- It is not suitable for the fluid measurement environment of continuous work, and frequent switching projects will have an impact;
- The range is narrow, and the general instrument has a range of 10:1.
- The accuracy is not very high, and it is generally used as a process control meter. It should be used with caution in trade settlement.
If you need a higher precision flowmeter, you can choose a Coriolis mass flow meter.
- It has drift (usually with compensation)
- It is easy to vibrate (usually with damping parts)
- The target piece is easy to fall off (due to operation)
