Electromagnetic flowmeter common troubleshooting methods
Check that the power supply has been connected, check whether the output voltage of the power circuit board is normal, or try to replace the entire power circuit board to determine whether it is good or bad. Check the cable is in good condition and the connection is correct. Check the direction of liquid flow and whether the liquid in the tube is full. For electromagnetic flow that can be measured in forward and reverse directions.
Caused by such failures are mostly caused by the measurement media or the external environment, the failure can be eliminated after the outside interference is eliminated. In order to ensure the accuracy of measurement, such failures cannot be ignored. In some production environments, due to the large vibration of the measuring pipe or liquid, the flowmeter's circuit board may be loosened and the output value may fluctuate. If it is confirmed that it is the reason of the process operation, the fluid does pulsate. In this case, the flow meter only accurately reflects the flow condition. After the pulsation is over, the fault can be eliminated by itself. Electromagnetic interference from external stray currents. Check whether there is a large-scale electric appliance or electric welding machine working in the instrument operating environment. Make sure that the instrument grounding and operating environment are good.
The closer the flow rate is to the center of the pipeline, the greater the flow rate in the center of the pipeline (because the wall friction reduces the velocity of the fluid flowing through the wall). So when the fluid flows through the V-cone flowmeter, the cone interacts directly with the high velocity center portion of the fluid, forcing the high velocity center to homogenize with the low velocity fluid near the tube wall, resulting in the correct differential pressure, which is even more at low flow rates. it works. However, in the case of differential pressure flowmeters (such as orifice plates) that are opened in other centers, because they do not have this effect, the pipes are not filled with liquid or bubbles are contained in the liquid, both of which are caused by the process. At this point, the craftsman can be requested to confirm that the output value can be restored to normal after the liquid is full or the bubble is calmed down. The transmitter circuit board is a plug-in structure. Due to the large vibration of the pipe or liquid in the field, the power board of the flow meter is often loosened. If loose, the flowmeter can be disassembled and the circuit board can be re-fixed.
　　
We need to know the common troubleshooting method of electromagnetic flowmeter
Instrument no-flow signal output causes analysis This type of fault is more common in the use of the process, the general reasons are: (1) instrument power supply is not normal; (2) cable connection is not normal; (3) liquid flow conditions do not meet the installation requirements; (4 ) The sensor component is damaged or there is an adhesive layer on the inner wall; (5) The converter component is damaged. The solution has a long life. The fluid flows through the cone without sudden fluctuations. Instead, it forms a boundary layer along the cone and guides the fluid away from the cone's back corner. This makes the cone angle free from the wear of dirty fluids. The flow coefficient β rate can be unchanged for a long time, and ensure long-term accurate measurement. Therefore, the flow meter can be used for a long period of time in a dirty place, and does not require regular maintenance and periodical verification (of course, regular maintenance and verification of the secondary watch is still necessary). Signal stability, due to the differential pressure generated by the throttling element, also leads to eddy currents after the element, so each differential pressure instrument has signal fluctuations, even if the fluid is stable. Check that the power supply has been connected, check whether the output voltage of the power circuit board is normal, or try to replace the entire power circuit board to determine whether it is good or bad. Check the cable is in good condition and the connection is correct. Check the direction of liquid flow and whether the liquid in the tube is full. For electromagnetic flowmeters that can measure both positive and negative directions, if the direction is not consistent, it can be measured, but the set display flow direction does not match, and must be corrected. If the disassembled sensor has a large workload, the direction of the arrow on the sensor can also be changed and the display instrument symbol can be reset. Pipeline not full of liquid is mainly caused by improper installation position of the sensor. Measures should be taken during installation to avoid causing the liquid in the pipe to be less than the pipe. Check whether the electrode on the inner surface of the transmitter is covered with a liquid coating layer. , to be cleaned regularly. If it is judged to be a fault caused by damage to the converter components, replacement of the damaged components can lead to low-frequency signal fluctuations due to the long eddy currents generated by the standard orifice plate, which seriously interferes with the accuracy of differential pressure readings. The eddy current produced by the V cone is very short, so the signal fluctuation is high frequency and low amplitude, which makes the V cone produce a stable signal.
Fluorocrystalline mica, also known as Fluorphlogopite Mica, synthetic mica, artificial mica, synthetic mica crystal, belongs to the silicate type artificial mica crystal, is under the high temperature condition of 1500°C, through strict process conditions and material ratio, in platinum The mica crystals smelted in the yttrium have a chemical formula of KMg3(AISi3O10)F2(OH)-, and do not contain (OH)-. The (OH)-hydroxyl group is replaced by F-(fluoro), which is similar to the fluorite mica. Materials commonly used in the general industry are natural mica. Natural mica is an underground ore naturally formed and belongs to the class of silicates. Most of the industrial mica used is phlogopite (brown) and muscovite. Its ideal chemical formula is KAI2(AISi3O10)(OH)2. OH)-(Hydroxy), due to the presence of hydroxyl (water molecules), its performance in all aspects is far lower than that of fluorocrystalline mica.
The main characteristics of fluoride crystal mica:
1, high temperature: can work long-term in the 1100 °C environment.
The testing department of the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences (nationally recognized testing institute) tested the thermal weight loss of 8% at 1100°C for 48 hours, and the melting and devitrification temperature was 1375°C.
2. Electrical insulation: The volume resistivity is 10 times higher than natural mica. Electrical breakdown strength is PTFE
Lean 10 times.
3, hot and cold blasting stability is very good
5 cycles of -40°C~70°C at the 5th Saibao Lab of the Ministry of Information Industry
Inspection, all qualified.
4, anti-corrosion:
Fluorophlogopite does not react with acid and alkali solutions, and does not react with water. Under the long-term (2 to 3 years) scouring of high-temperature and high-pressure water (including acid and alkali), the original clarity and transparency can still be maintained.
5, high frequency performance:
The dielectric constant of fluorite mica is 4.6 ε, and the dielectric loss is (1~4)×10 −4 tg δ, and the dielectric loss is very low. And because of the pure texture, all parameters are extremely stable.
6, optical properties
Since the fluorite mica contains less impurities, its light transmittance is compared from infrared to ultraviolet.
High, the transmittance is close to 100%.
7, Mosaic (Mosaicity):
The Mosaicite of fluorocrystalline mica is less than 0.25 degrees, which was produced in the experiment.
The neutron flame is not high enough to absorb multi-band light beams and is an ideal neutron monochromator test material.
8, vacuum deflation performance:
The evaporative volume of fluorite mica is low, and it is measured with a mass spectrometer and the trace gas released is only
O2, N2, Ar and other adsorbed gases. Since the H2O vapor is not released, this is extremely valuable for use as an electrical vacuum insulation material, which can greatly increase the service life of the vacuum device.
9, excellent physical properties:
Fluorocrystalline mica has atomicity flatness, transparency, separability and elasticity, not aging
It is not brittle and so on.
Due to the high temperature resistance, corrosion resistance, low frequency loss, and high bulk resistivity
Absorb multi-band light beam, excellent light transmittance and other advantages. Therefore it has become an ideal new material in the high-end area.
Fluorocrystalline mica Available in:
In the range of 180mm×53mm or ∮76mm, it can be processed into various shapes according to user requirements. Thickness within the range of 0.02mm~1.0mm can be allocated according to user requirements. The conventional thickness is 0.04~0.2mm.
Fluorine crystal (fluorphlogopite, artificial mica) mica film for observation window of high pressure boiler water level gauge in thermal power plant
Fluorphlogopite Mica
Fluorophlogopite Mica,Fluorophlogopite Sheet,Synthetic Fluorophlogopite Mica,Fluorophlogopite Mica Fragments
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