DN150 sewage flowmeter measurement error caused by what factors?

DN150 sewage flow meter is a flow meter that measures flow. If the sewage flow meter does not measure well, it is equivalent to a waste product, so the measurement accuracy of the sewage flow meter is very important. So what are the factors that affect the measurement accuracy of the sewage flow meter? Here is a small introduction from Smet: a. Improper installation of the DN150 sewage flow meter introduces errors. Installed near external strong electromagnetic fields, such as large motors, high-power frequency converters, large transformers and other equipment, the fluid in the measuring tube will have strong stray currents, affecting the accuracy of the measurement. It is recommended to adopt measures such as electromagnetic shielding and good grounding. The length of the upstream and downstream straight pipe sections of the sewage flow meter is not enough, and the fluid flow is an underdeveloped turbulent flow, which causes the induced electromotive force to change. It is recommended to install a flow regulator. The process pipe section has low-frequency pulsating flow, for example, the rotation of the mixer blades, etc., causing the flow to oscillate at low frequencies. For this reason, the flow meter should be installed away from the vibration source. There is a two-phase flow in the pipe. For example, if the liquid to be measured contains gas and the gas to be measured contains liquid, and the liquid is not drained and vented in front of the measuring tube, the conductivity will change and measurement errors will be introduced. The fluid contains solid particles, causing slurry noise. A drain valve should be installed at the lowest point of the measuring pipe section, and an exhaust valve should be installed at the highest position of the measuring pipe section. The sewage flow meter was not well grounded and was damaged by lightning surge current. Therefore, the sewage flow meter must be well grounded according to the product instructions and the grounding ring must be connected. The electrode material selected is inappropriate and may cause electrode surface effects with the fluid. Improper installation location, for example, downstream of the chemical liquid injection point or pipeline reactor section, makes the fluid conductivity uneven and introduces errors. For this reason, there should be enough pipe sections downstream of the chemical liquid injection point or pipeline reactor section to allow the fluid to Mix thoroughly. Installed in places where the pipe is not full, for example, on a vertical pipe from top to bottom; liquid without back pressure is directly discharged into the atmosphere, etc. The inner diameter difference between the installed process pipe and the flowmeter measuring pipe is too large, the axis is eccentric during installation or the installed gasket protrudes into the pipe.

b. Improper use of the DN150 sewage flow meter may introduce errors. The dirt carried by the fluid contaminates the electrode, or the conductivity of the attachment is inconsistent with the conductivity of the fluid, making the measurement inaccurate. A filter should be installed to remove contaminants and clean the electrodes. The fluid is a pulsating flow, causing the output to fluctuate. The sewage flow meter should be installed far away from the source of the pulsating flow, such as far away, etc., and a damping or buffer container should be installed. For the control valve installed downstream of the flow meter, the controller parameters should be adjusted so that Its opening changes smoothly. The sewage flowmeter operates in a non-full pipe state without adopting non-full pipe operation measures, resulting in measurement errors. Signal cables and power cables are laid together without isolation measures, causing electromagnetic interference. They should be laid separately and isolated, and have good grounding. The flow meter was struck by lightning, causing damage to the flow meter. If the signal cable insulation is degraded, short-circuited, grounded, etc., the cable insulation should be checked regularly and unqualified cables should be replaced. Sensor failure. Wrong wiring, unused or damaged sensor cable, converter failure, etc. The lining is damaged, the insulation is degraded, and the electrodes are damaged, resulting in measurement errors or failure to use. Replace and recalibrate.