How should the air traffic threshold of electromagnetic flowmeter be set?
Fluid level pipe dropped from full pipe state to the empty state, there will be a fluid wall phenomenon, which cause the meter measurement ATC cannot follow the fluid level reached the maximum immediately, but there is a time of transition, corresponding to the time and wall fluid retention time. So, in actual use, if you want to make instrument air pipe alarm faster response, you can set the alarm threshold of air traffic control smaller, such as about 500%.
The measured value of air pipe is calculated by relative resistivity, and the resistivity value of fluid in full pipe state is defined as 100%, that is, when the pipe is full of fluid, the air duct measurement value is calibrated to 100% by air traffic alarm threshold. When the fluid level in the pipeline is lower than the measuring electrode, the electrode contacts the air, and the relative resistivity will increase. When the alarm threshold is higher than that of the air pipe, the meter will show the air traffic alarm signal.According to the actual usage statistics, in fluid filled pipes, the ATC measurements calibrated to 100%, when the pipeline fluid level completely below the measuring electrode (electrode contact fluid), ATC measurements will reach more than 1000%. Therefore, the air traffic control alarm value is set at about 900%, and the air traffic control state can be accurately reported.
Usually set in the range of 500%~999% (different manufacturers may differ, with product specification shall prevail), fluid resistivity sensor for real-time measurement of value is in full state, do so to judge pipeline, air traffic control measurement is a continuous value. Although different fluids have different resistivity values, the resistivity values are stable as long as the fluid is in the full tube state.
The reason of flow rate in electromagnetic flowmeter:1, instrument housing grounding ready.2, ATM verification function to open up, in the processparameter menu, there should be a EPD open, just fine.3, small signal resection, flowmeter in air traffic or low flow may occur false signal, so generally want to small signal resection.
