How to troubleshoot the problem during the use of electromagnetic flowmeter?

1. Check whether the power supply voltage is correct in the working area. 2. Whether the sensor ground is reliable or damaged; 3. Whether the media is full of sensors and whether there are bubbles in the medium; 4. Is the reading correct and the measured value within the range of measurement? 5. Is the terminal connection loose? 6. Is the flow sensor immersed in water? How to troubleshoot the electromagnetic flowmeter: 1. 2. Check whether the power supply is connected; 3. Check whether the power fuse is in good condition; 4. Check whether the power supply voltage meets the requirements; 5. Check whether the contrast adjustment of the monitor can be adjusted and adjusted. The causes of electromagnetic flowmeter failure are caused by the following aspects: environment; Fluids; Installation. Environmental reasons: it is mainly due to the interference of stray current in the pipeline, the interference of strong space electromagnetic waves, and the interference of large electromagnetic fields. Pipeline stray current interference usually take good separate grounding protection can obtain satisfactory results, but if strong stray current (such as electrolytic workshop pipeline, sometimes in two electrode induction ac peak potential Vpp can be as high as 1 v), still need to take other measures and flow sensor and pipe insulation, etc. Space electromagnetic interference is usually introduced by signal cable, and it is usually protected by single layer or multi-layer shielding. Fluid reasons: the uniform distribution of tiny air bubbles in the liquid to be measured is usually does not affect the normal work of the electromagnetic flowmeter, but with the increase of air bubbles, the volatility meter output signal, if the bubble is big enough to cover the entire electrode surface, as the bubble through the electrodes can make electrode circuit instantaneous trip and make the output signals appear larger fluctuation. When the electromagnetic flowmeter of low-frequency square wave excitation is measured, the slurry noise will also be produced to produce the fluctuation of the output signal. When measuring the mixing medium, the output signal will be fluctuated if the flow sensor is measured before the mixing is not even. Improper selection of electrode materials and measured media will also affect normal measurement due to chemical or polarization phenomena. The electrode material should be selected according to the instrument selection or relevant manual. Reasons for installation: usually the fault caused by incorrect installation position of the electromagnetic flow sensor, such as the installation of the sensor to the highest point of the piping system in which the gas is easily accumulated; Or install on top down vertical pipe, may appear emptying; Or no back pressure after the sensor, the fluid is directly discharged into the atmosphere and the measurement tube is not filled. Method for troubleshooting of electromagnetic flowmeter: resistance method; Current method; Voltage method; Alternative method; Analog signal method; Waveform method. Resistance method :(1) flow meter power fuse, excitation insurance pass-through; (2) transmission of electromagnetic flowmeter signal cable and excitation cable; (3) the circuit breaker and resistance value of the electromagnetic flowmeter excitation coil; (4) insulation resistance of electromagnetic flowmeter excitation coil to ground; (5) electrode symmetry measurement; (6) insulation resistance of the electrode to the ground; (7) resistance of flow meter power transformer. Current method: flowmeter measurement output current, field current and voltage method: judgment work power, alternative method: if the flowmeter converter, swapping amplification board, analog signal method: using analog signal generator provides flow signal, to test the flow sensor, waveform method: familiar with the line on the basis of electromagnetic flowmeter test key waveforms inspection content is: appearance inspection, the converter characteristic test, measurement calibration, measurement of each voltage, measure the insulation resistance, confirm the circuit, etc. The adjustment of the meter is very important because of the zero drift, and the adjustment of the zero point is very important (" online zero "must stop the flow of the measured media, which is actually not easy to do). Online inspection, therefore, are often omitted contains a check of the operation of the sensor and only implement the converter calibration, so that the online test results and historical data comparison instrument is to continue to use, repair, or update, the excitation coil of sensor is measured insulation resistance degradation decided to update or not. Check and verify that the electromagnetic flowmeter is abnormal. To can't stop medium flow pipeline check the flow sensor and converter respectively, with analog signals and other common instrument testing converter has higher calibration accuracy (depending on the analog signal accuracy), liquid resistance sensor examination is to test the electrode, including check the excitation coil excitation connecting cable and copper resistance, insulation resistance and check, the excitation current converter output check the indirect methods, such as magnetic field intensity. For the pipeline that can stop the flow condition of the medium, it can enter the hole in the vicinity of the sensor, check the electrical level and the lining of the dirt/deposition condition and clean. Electromagnetic flowmeter zero check machine: the flow sensor tube filled with liquid and there is no flow, at the scene of the many companies do not have this condition instead of zero check and adjustment of the machine, but can be turned to the converter separate zero check and adjustment. Technically, this must be the sensor check finished and to ensure that the sensor excitation circuit and signal circuit is normal (both included) cable insulation resistance is under the premise of practical significance, otherwise the machine cannot run normally. Normally, the converter is negative and the value is small. If its absolute value is greater than 5% of the full range, it needs to be checked first and then adjusted after the reason is confirmed. In general, the zero point difference between the zero and the converter of the electromagnetic flowmeter is less than 1%. More than 5% of the difference value of zero is due to the improper operation of the valve when the valve is closed. Electromagnetic flowmeter connecting cable inspection: the inspection content is to check the insulation resistance of each conductor of the signal line and excitation wire, and check whether the grounding of each shielding layer is in good condition. Electromagnetic flowmeter converter inspection: the inspection content is used to replace the sensor with the analog signal device matching the general instrument and the flowmeter model to adjust and adjust the flow signal. Calibration includes zero check and adjustment, set value check, excitation current measurement, current/frequency output check, etc. It is important to note that the inspection items should be compared with the last check value (or factory value) to see if any changes or changes are in line with the original measurement requirements. Electromagnetic flowmeter sensor inspection: check the copper resistance of the excitation coil; Check the insulation resistance of the excitation coil; Check the electrode junction resistance; Check the polarization voltage between electrode/liquid; Check the insulation between the signal circuit and the excitation circuit/signal circuit.