Flow meter measures the difference

What is the flow rate range? For a value of 200–300 cubic meters, what is the approximate percentage error? Is it within the error range of the flow meter itself?

It’s necessary to explain how many cubic meters flow in total per day,,,

First, check whether the percentage difference is within the allowable tolerance of the flow meter; if it is beyond that range, verify whether the setting parameters are correct. Additionally, examine whether there is vibration or electromagnetic interference at the installation location that could affect measurement accuracy.

It could be due to errors in the flow meter, or it might be that flow meters from different manufacturers also have errors; furthermore, differences in operating conditions can also cause errors

Add a pressure transmitter to the flow meter at the back to perform pressure compensation

Vortex flow meters are used for frequency measurement; attention must be paid to the installation method and vibrations. Flow rate is also a key factor – it’s best not to have it too low or too high. The properties of the medium must also be taken into account; for gases, temperature and pressure compensation is necessary

When the fluid passes through a vortex generator composed of spiral blades, it is forced to rotate violently around the axis of the generator, forming a vortex. When the fluid enters the diffusion section, the vortex flow is affected by the backflow and begins to rotate again, resulting in a gyroscopic vortex precession phenomenon. This precession frequency is proportional to the flow rate and is unaffected by the physical properties and density of the fluid. By measuring the secondary rotational precession frequency of the fluid with the sensing element, the flow rate can be determined. Moreover, it achieves good linearity over a wide range of flow rates. The flow rate calculation formula is: K = f/q, where K is the coefficient of the flow meter in units of l/m³, f is the vortex frequency in Hz, and q is the volumetric flow rate in m³/s. Generally speaking, the following points should be taken into account when installing and using vortex flow meters. 1) Select a suitable installation location. The installation location should be kept away from high-power equipment, high-frequency devices, and powerful power switching equipment; it should also be free from the influence of high-temperature heat sources and radiant heat sources, as well as high-temperature and highly corrosive atmospheres. Additionally, the area should be free from intense vibrations, and installation, wiring, and maintenance should be easy to carry out. Upstream and downstream of the sensor, vibrations caused by overly long pipes must be eliminated. 2) The instrument should generally be installed horizontally, and the flow direction of the fluid being measured should be consistent with the arrow indicating the flow direction on the housing. It can also be installed vertically or at an angle. When measuring liquids, it is necessary to ensure that the sensor is always completely filled with liquid. To prevent disruptions to the normal flow of fluid during maintenance, it is recommended to install an additional bypass at the section where the instrument is mounted. 3) Rotary vortex flowmeters have relatively low requirements regarding the straight pipe sections before and after them. In principle, it is not necessary to have straight pipe sections before or after the flowmeter, but generally, a straight pipe section with a length of 3D is required in front of the instrument, and one with a length of 1D is required behind it. Special cases require 5D and 3D lengths. When the bend radius of a single or double bend is greater than 1.8D, straight sections before and after the flowmeter are not required. 4) Temperature and pressure compensation can be used when measuring gases or vapors. 5) When the fluid under test contains impurities, a strainer or filter screen should be installed in front of the instrument; however, the requirement for a straight pipe section in front of the instrument must still be met. 6} Method of sensor installation when measuring small amounts of heterogeneous gas-liquid two-phase flow. When measuring liquids, there may be a small amount of gas phase in the pipeline, with its content not exceeding that allowed for gas-liquid two-phase fluids. To prevent gas from remaining inside the sensor, a gas separator must be installed. When measuring gases, if the pipeline may be filled with condensate generated by the gas being measured, or if there are unstable liquid phases present in the gas that have not been removed, it is best to install it vertically in order to prevent liquids from remaining inside the sensor. When measuring high- or low-temperature fluids, the sensor itself must have effective holding mechanisms. 7) The volumetric flow rate of the gas under measurement as indicated by the instrument is the actual flow rate of that gas under operating conditions. If this actual flow rate is converted to a standard flow rate under standard conditions, it can be calculated using the following formula: where 4‑p represents the volumetric flow rate under standard conditions; 4 represents the volumetric flow rate under operating conditions; ho is the absolute pressure of the gas being measured under standard conditions; To is the thermodynamic temperature of the gas being measured under standard conditions; ho also represents the absolute pressure of the gas under operating conditions; T represents the thermodynamic temperature of the gas under operating conditions; and Z is the compressibility factor of the gas under operating conditions. 8) When the pipeline is long and vibration may occur, fixed supports should be installed upstream and downstream of the flow meter to prevent pipeline vibration. Based on experience, flow measurement values are susceptible to airflow fluctuations and pressure changes. 9) The volumetric flow meter coefficient Kvn and the mass flow meter coefficient Km are determined through calibration at normal temperature before the instrument leaves the factory. When the operating condition of the instrument differs significantly from the calibration condition in the laboratory, the instrument coefficients K and K’ must be corrected. The method for correcting these coefficients is the same as that used for vortex flowmeters.

Whether it is a gas; pay attention to temperature and pressure compensation, or check whether the liquid vaporizes after pressure reduction

Let’s look at these aspects: 1. Do both flow meters have temperature and pressure compensation (for overheating and saturation)? 2 Are the steam traps in front of the two flow meters functioning properly for steam drainage? 3 Confirm the distance between flow meter B and the temperature and pressure reducing valve to ensure that vibrations can be avoided.