FAQ
Precautions for field use
1, digital pressure gauge field use conditions should meet the requirements of the instrument technical parameters. The correct selection of the instrument range, the measured pressure can not exceed the measuring upper and lower limits of the instrument, should leave sufficient overpressure safety margin
2, the temperature of the measured medium of the pressure gauge shall not exceed the operating temperature of the instrument, and the sealing and vibration resistance of the instrument should be ensured when used in corrosion and vibration places.
3, the digital precision pressure gauge is vertically downward direct installation type, can be directly installed on the pressure interface of the pipeline to be measured, installation to avoid the formation of a "closed pressure" between the instrument connection thread and the valve in front of the table (observe the value, pay attention to the pressure response time), if the formation of the pressure, should be eliminated in time, otherwise it will cause damage to the measuring element, media leakage.
Operating Instructions
The sensor and display processing part of the digital pressure gauge adopts an integrated design structure, which is easy to use. The digital pressure gauge is directly connected to the measured mechanism using threads, and there is no requirement for the placement angle of the digital pressure gauge. The approximate pressure range of the target to be measured should be estimated to avoid mechanical damage to the sensor due to excessive pressure exceeding the measurement range. The pressure response time of the digital pressure gauge is 2S.
Troubleshooting and troubleshooting
Digital pressure gauges are mechanical and electrical products. During transportation and use, due to environmental interference and improper human operation, the instrument may not work and display normally. For simple faults, users can eliminate them by themselves, and other faults need to be returned to the manufacturer for maintenance. The list below indicates the faults and their troubleshooting methods.
Trouble shooting method of digital pressure gauge
1. There is no font on the screen to replace the battery
2. The font does not change when the pressure increases, take out the battery, wait for 30 seconds, and then reinstall it
3. If the font is non-digital, the liquid crystal is damaged and returned to the factory for repair.
4. The value is obviously inaccurate, the sensor is damaged, return to the factory for repair.
5. If the accuracy changes, return to the factory for recalibration
Performance analysis of intelligent digital pressure gauge!
1. Economic benefit analysis
After long-term operation, the intelligent digital pressure gauge shows that the failure rate is low, the maintenance cost is less, and the operating cost is reduced. Maintenance workload is small, mainly for regular check and verification. Even if there is a problem, you can easily find the problem through hand exercises to reduce unnecessary waste. The price of intelligent digital pressure gauge is relatively higher than that of ordinary pressure gauge, although it increases the cost, but its service life, accuracy grade and so on are much higher than that of traditional pressure gauges.
2. Analysis of technological advancement
The intelligent digital pressure gauge has few moving parts, small maintenance workload, high precision, reliable operation, convenient setting, correction and debugging through hand operation, with strong operability and compatibility, easy debugging, multi-parameter measurement, wide measurement range.
3. Precautions
The intelligent digital pressure gauge must be consistent with the on-site installation position during indoor verification, otherwise a large zero error will be generated.
4. Closing remarks
After long-term use by customers, intelligent digital pressure gauges have a wide range of uses in industry, petrochemical and other fields, and it is also an inevitable trend in the future development of field instruments. It is of great significance to save and reduce cost and improve economic benefit.
Contact:
Many industries are gradually using electronic pressure gauges, which is what we usually call pressure transmitters, but due to the working environment, media, media temperature and so on, we must consider these issues when choosing pressure transmitters. Now I will talk about the purchase of pressure transmitters.
1, liquid material
We have to consider the pressure transducer measured by the medium, the general pressure transmitter contact medium part of the material used is 316 stainless steel, if your medium is not corrosive to 316 stainless steel, then basically all the pressure transmitters are suitable for your measurement of medium pressure. If your medium is corrosive to 316 stainless steel, then we must use a chemical seal, so that not only can measure the pressure of the medium, but also can effectively prevent the contact between the medium and the liquid part of the pressure transmitter, so as to protect the pressure transmitter and extend the life of the pressure transmitter.
2, accuracy level
Each kind of electronic measuring meter will have accuracy errors, but because the accuracy level of each country is not the same, for example, the accuracy of China and the United States and other countries is the best part of the linearity of the sensor, that is, the accuracy of the measurement range we usually say between 10% and 90%; The accuracy of the European target is the worst part of linearity, that is, we usually say that the accuracy of the measurement is between 0 and 10% and 90% to 100%. If the accuracy of the European target is 1%, the accuracy of the target in China is 0.5%, and the accuracy level of the pressure transmitter developed by Shanghai Yongwei Automatic Control Complete Equipment Co., Ltd. is 0.2.
3. Range range
Generally, the maximum range measured by the sensor is 70% of the full scale of the sensor is the best, that is, to measure the pressure of 70bar, we choose the range of the pressure transmitter should choose 100bar.
4, output signal
At present, due to the needs of various collection, there are many kinds of output signals of pressure transmitters on the market, mainly 4~20mA,0~20mA,0~10V,0~5V, etc., but the more commonly used are 4~20mA and 0~10V two, in these output signals I mentioned above, only 4~20mA is a two-wire system (we say the output is several The wire system does not include ground or shielded wires), and the others are three-wire systems.
5, medium temperature
Because the signal of the pressure transmitter is partially converted through the electronic circuit, under normal circumstances, the temperature of the measuring medium of the pressure transmitter is -30 to +100 degrees, if the temperature is too high, we generally use the condensation bend to cool the medium, so that the cost of the manufacturer specially for you to produce a high temperature pressure transmitter will be reduced a lot.
6. Measure the medium
Generally, we measure a relatively clean fluid, we directly use a standard pressure transmitter on it, if the medium you are measuring is easy to crystallize or sticky, we generally use an external diaphragm or chemical seal together, which will effectively prevent the medium from blocking the pressure measurement hole.
7. Others
After determining the above five parameters, also confirm the process connection interface of your pressure transmitter and the supply voltage of the pressure transmitter; If it is used in special occasions, explosion protection and protection level should be considered.
Contact:
Smart electromagnetic flowmeter is a speed instrument. In addition to measuring the volume flow of general conductive liquids, it can also be used to measure the volume flow of strong corrosive liquids such as strong acids and alkalis, and uniform liquid-solid two-phase suspension liquids such as mud, ore pulp, and paper pulp. Widely used in petroleum, chemical industry, metallurgy, light textile, papermaking, environmental protection, food and other industrial sectors and municipal management, water conservancy construction, river dredging and other fields of flow measurement. Common faults, some are caused by damage to the components of the instrument itself, and some are caused by improper selection, improper installation, environmental conditions, fluid characteristics and other factors, such as display fluctuations, decreased accuracy, and even instrument damage. It can generally be divided into two types: failures that occur during installation and debugging (debugging period failures) and failures that occur during normal operation (running period failures).
(1) Faults in the debugging period Debugging is expected that faults generally appear in the stage of instrument installation and debugging. Once eliminated, they will generally not reappear under the same conditions in the future. Common failures during the commissioning period are generally caused by improper installation, environmental interference, and influence of fluid characteristics.
1) In terms of installation, it is usually caused by the incorrect installation position of the smart electromagnetic flowmeter sensor. Commonly, such as installing the sensor at the highest point of the piping system where gas is easy to accumulate; or installing it on a vertical pipe from top to bottom, there may be discharge Empty; or there is no back pressure behind the sensor, and the fluid is directly discharged into the atmosphere to form a part of the measuring tube.
2) The environmental aspect is usually mainly the interference of stray current in the pipeline, the interference of strong electromagnetic waves in the space, and the interference of the magnetic field of large motors. Pipeline stray current interference usually takes a good separate grounding protection to obtain satisfactory results, but if encountering strong stray currents such as electrolytic workshop pipelines, sometimes the peak value of the AC potential induced on the two electrodes can be as high as The flow sensor is insulated from the pipe, etc. Space electromagnetic wave interference is generally introduced through signal cables, and is usually protected by single-layer or multi-layer shielding.
3) In terms of fluid, evenly distributed tiny bubbles in the measured liquid usually do not affect the normal operation of the electromagnetic flow meter, but as the bubbles increase, the output signal of the meter will fluctuate. If the bubbles are large enough to cover the entire electrode surface, As the air bubbles flow through the electrode, the electrode circuit will be momentarily disconnected, causing greater fluctuations in the output signal.
When the electromagnetic flow meters with low frequency square wave excitation measures the slurry with too much solid content, it will also generate slurry noise, which will cause the output signal to fluctuate.
When measuring mixed media, if the flow sensor is used for measurement before the mixing is not uniform, the output signal will also fluctuate.
Improper selection of the electrode material and the measured medium will also affect the normal measurement due to chemical action or polarization.
(2) Faults during the operation period Faults during the operation period are faults that occur after the intelligent electromagnetic flow meter has been debugged and operated normally for a period of time. Common faults during the operation period are generally caused by factors such as the adhesion layer on the inner wall of the flow sensor, lightning strikes, and changes in environmental conditions.
1) Adhesion layer on the inner wall of the sensor As electromagnetic flowmeters are often used to measure dirty fluids, after a period of operation, an adhesion layer will often accumulate on the inner wall of the sensor and cause failure. These failures are often caused by the conductivity of the adhesion layer being too large or too small. If the attachment is an insulating layer, the electrode circuit will be disconnected and the meter will not work normally; if the conductivity of the adhesion layer is significantly higher than that of the fluid, the electrode circuit will be short-circuited and the meter will not work normally. Therefore, the attached scaling layer in the measuring tube of the electromagnetic flowmeter should be removed in time.
2) Lightning strike Lightning strike is easy to induce high voltage and surge current in the instrument circuit, which will damage the instrument. It is mainly introduced through the power line or the excitation coil or the flow signal line between the sensor and the converter, especially from the control room power line, which accounts for the vast majority.
3) Changes in environmental conditions During commissioning, because the environmental conditions are still good (for example, there is no interference source) the flowmeter works normally, and it is often easy to ignore the installation conditions at this time (for example, the grounding is not very good). In this case, once the environmental conditions change, the operation During this period, new interference sources (such as electric welding on the pipeline near the flowmeter, large transformers installed nearby, etc.) will interfere with the normal operation of the instrument, and the output and output signals of the flowmeter will fluctuate.
Contact:
Smart electromagnetic flowmeter is a speed instrument. In addition to measuring the volume flow of general conductive liquids, it can also be used to measure the volume flow of strong corrosive liquids such as strong acids and alkalis, and uniform liquid-solid two-phase suspension liquids such as mud, ore pulp, and paper pulp. Widely used in petroleum, chemical industry, metallurgy, light textile, papermaking, environmental protection, food and other industrial sectors and municipal management, water conservancy construction, river dredging and other fields of flow measurement. Common faults, some are caused by damage to the components of the instrument itself, and some are caused by improper selection, improper installation, environmental conditions, fluid characteristics and other factors, such as display fluctuations, decreased accuracy, and even instrument damage. It can generally be divided into two types: failures that occur during installation and debugging (debugging period failures) and failures that occur during normal operation (running period failures).
(1) Faults in the debugging period Debugging is expected that faults generally appear in the stage of instrument installation and debugging. Once eliminated, they will generally not reappear under the same conditions in the future. Common failures during the commissioning period are generally caused by improper installation, environmental interference, and influence of fluid characteristics.
1) In terms of installation, it is usually caused by the incorrect installation position of the smart electromagnetic flowmeter sensor. Commonly, such as installing the sensor at the highest point of the piping system where gas is easy to accumulate; or installing it on a vertical pipe from top to bottom, there may be discharge Empty; or there is no back pressure behind the sensor, and the fluid is directly discharged into the atmosphere to form a part of the measuring tube.
2) The environmental aspect is usually mainly the interference of stray current in the pipeline, the interference of strong electromagnetic waves in the space, and the interference of the magnetic field of large motors. Pipeline stray current interference usually takes a good separate grounding protection to obtain satisfactory results, but if encountering strong stray currents such as electrolytic workshop pipelines, sometimes the peak value of the AC potential induced on the two electrodes can be as high as The flow sensor is insulated from the pipe, etc. Space electromagnetic wave interference is generally introduced through signal cables, and is usually protected by single-layer or multi-layer shielding.
3) In terms of fluid, evenly distributed tiny bubbles in the measured liquid usually do not affect the normal operation of the electromagnetic flow meter, but as the bubbles increase, the output signal of the meter will fluctuate. If the bubbles are large enough to cover the entire electrode surface, As the air bubbles flow through the electrode, the electrode circuit will be momentarily disconnected, causing greater fluctuations in the output signal.
When the electromagnetic flow meters with low frequency square wave excitation measures the slurry with too much solid content, it will also generate slurry noise, which will cause the output signal to fluctuate.
When measuring mixed media, if the flow sensor is used for measurement before the mixing is not uniform, the output signal will also fluctuate.
Improper selection of the electrode material and the measured medium will also affect the normal measurement due to chemical action or polarization.
(2) Faults during the operation period Faults during the operation period are faults that occur after the intelligent electromagnetic flow meter has been debugged and operated normally for a period of time. Common faults during the operation period are generally caused by factors such as the adhesion layer on the inner wall of the flow sensor, lightning strikes, and changes in environmental conditions.
1) Adhesion layer on the inner wall of the sensor As electromagnetic flowmeters are often used to measure dirty fluids, after a period of operation, an adhesion layer will often accumulate on the inner wall of the sensor and cause failure. These failures are often caused by the conductivity of the adhesion layer being too large or too small. If the attachment is an insulating layer, the electrode circuit will be disconnected and the meter will not work normally; if the conductivity of the adhesion layer is significantly higher than that of the fluid, the electrode circuit will be short-circuited and the meter will not work normally. Therefore, the attached scaling layer in the measuring tube of the electromagnetic flowmeter should be removed in time.
2) Lightning strike Lightning strike is easy to induce high voltage and surge current in the instrument circuit, which will damage the instrument. It is mainly introduced through the power line or the excitation coil or the flow signal line between the sensor and the converter, especially from the control room power line, which accounts for the vast majority.
3) Changes in environmental conditions During commissioning, because the environmental conditions are still good (for example, there is no interference source) the flowmeter works normally, and it is often easy to ignore the installation conditions at this time (for example, the grounding is not very good). In this case, once the environmental conditions change, the operation During this period, new interference sources (such as electric welding on the pipeline near the flowmeter, large transformers installed nearby, etc.) will interfere with the normal operation of the instrument, and the output and output signals of the flowmeter will fluctuate.
Contact:
Smart electromagnetic flowmeter is a speed instrument. In addition to measuring the volume flow of general conductive liquids, it can also be used to measure the volume flow of strong corrosive liquids such as strong acids and alkalis, and uniform liquid-solid two-phase suspension liquids such as mud, ore pulp, and paper pulp. Widely used in petroleum, chemical industry, metallurgy, light textile, papermaking, environmental protection, food and other industrial sectors and municipal management, water conservancy construction, river dredging and other fields of flow measurement. Common faults, some are caused by damage to the components of the instrument itself, and some are caused by improper selection, improper installation, environmental conditions, fluid characteristics and other factors, such as display fluctuations, decreased accuracy, and even instrument damage. It can generally be divided into two types: failures that occur during installation and debugging (debugging period failures) and failures that occur during normal operation (running period failures).
(1) Faults in the debugging period Debugging is expected that faults generally appear in the stage of instrument installation and debugging. Once eliminated, they will generally not reappear under the same conditions in the future. Common failures during the commissioning period are generally caused by improper installation, environmental interference, and influence of fluid characteristics.
1) In terms of installation, it is usually caused by the incorrect installation position of the smart electromagnetic flowmeter sensor. Commonly, such as installing the sensor at the highest point of the piping system where gas is easy to accumulate; or installing it on a vertical pipe from top to bottom, there may be discharge Empty; or there is no back pressure behind the sensor, and the fluid is directly discharged into the atmosphere to form a part of the measuring tube.
2) The environmental aspect is usually mainly the interference of stray current in the pipeline, the interference of strong electromagnetic waves in the space, and the interference of the magnetic field of large motors. Pipeline stray current interference usually takes a good separate grounding protection to obtain satisfactory results, but if encountering strong stray currents such as electrolytic workshop pipelines, sometimes the peak value of the AC potential induced on the two electrodes can be as high as The flow sensor is insulated from the pipe, etc. Space electromagnetic wave interference is generally introduced through signal cables, and is usually protected by single-layer or multi-layer shielding.
3) In terms of fluid, evenly distributed tiny bubbles in the measured liquid usually do not affect the normal operation of the electromagnetic flow meter, but as the bubbles increase, the output signal of the meter will fluctuate. If the bubbles are large enough to cover the entire electrode surface, As the air bubbles flow through the electrode, the electrode circuit will be momentarily disconnected, causing greater fluctuations in the output signal.
When the electromagnetic flow meters with low frequency square wave excitation measures the slurry with too much solid content, it will also generate slurry noise, which will cause the output signal to fluctuate.
When measuring mixed media, if the flow sensor is used for measurement before the mixing is not uniform, the output signal will also fluctuate.
Improper selection of the electrode material and the measured medium will also affect the normal measurement due to chemical action or polarization.
(2) Faults during the operation period Faults during the operation period are faults that occur after the intelligent electromagnetic flow meter has been debugged and operated normally for a period of time. Common faults during the operation period are generally caused by factors such as the adhesion layer on the inner wall of the flow sensor, lightning strikes, and changes in environmental conditions.
1) Adhesion layer on the inner wall of the sensor As electromagnetic flowmeters are often used to measure dirty fluids, after a period of operation, an adhesion layer will often accumulate on the inner wall of the sensor and cause failure. These failures are often caused by the conductivity of the adhesion layer being too large or too small. If the attachment is an insulating layer, the electrode circuit will be disconnected and the meter will not work normally; if the conductivity of the adhesion layer is significantly higher than that of the fluid, the electrode circuit will be short-circuited and the meter will not work normally. Therefore, the attached scaling layer in the measuring tube of the electromagnetic flowmeter should be removed in time.
2) Lightning strike Lightning strike is easy to induce high voltage and surge current in the instrument circuit, which will damage the instrument. It is mainly introduced through the power line or the excitation coil or the flow signal line between the sensor and the converter, especially from the control room power line, which accounts for the vast majority.
3) Changes in environmental conditions During commissioning, because the environmental conditions are still good (for example, there is no interference source) the flowmeter works normally, and it is often easy to ignore the installation conditions at this time (for example, the grounding is not very good). In this case, once the environmental conditions change, the operation During this period, new interference sources (such as electric welding on the pipeline near the flowmeter, large transformers installed nearby, etc.) will interfere with the normal operation of the instrument, and the output and output signals of the flowmeter will fluctuate.
Contact:
Smart electromagnetic flowmeter is a speed instrument. In addition to measuring the volume flow of general conductive liquids, it can also be used to measure the volume flow of strong corrosive liquids such as strong acids and alkalis, and uniform liquid-solid two-phase suspension liquids such as mud, ore pulp, and paper pulp. Widely used in petroleum, chemical industry, metallurgy, light textile, papermaking, environmental protection, food and other industrial sectors and municipal management, water conservancy construction, river dredging and other fields of flow measurement. Common faults, some are caused by damage to the components of the instrument itself, and some are caused by improper selection, improper installation, environmental conditions, fluid characteristics and other factors, such as display fluctuations, decreased accuracy, and even instrument damage. It can generally be divided into two types: failures that occur during installation and debugging (debugging period failures) and failures that occur during normal operation (running period failures).
(1) Faults in the debugging period Debugging is expected that faults generally appear in the stage of instrument installation and debugging. Once eliminated, they will generally not reappear under the same conditions in the future. Common failures during the commissioning period are generally caused by improper installation, environmental interference, and influence of fluid characteristics.
1) In terms of installation, it is usually caused by the incorrect installation position of the smart electromagnetic flowmeter sensor. Commonly, such as installing the sensor at the highest point of the piping system where gas is easy to accumulate; or installing it on a vertical pipe from top to bottom, there may be discharge Empty; or there is no back pressure behind the sensor, and the fluid is directly discharged into the atmosphere to form a part of the measuring tube.
2) The environmental aspect is usually mainly the interference of stray current in the pipeline, the interference of strong electromagnetic waves in the space, and the interference of the magnetic field of large motors. Pipeline stray current interference usually takes a good separate grounding protection to obtain satisfactory results, but if encountering strong stray currents such as electrolytic workshop pipelines, sometimes the peak value of the AC potential induced on the two electrodes can be as high as The flow sensor is insulated from the pipe, etc. Space electromagnetic wave interference is generally introduced through signal cables, and is usually protected by single-layer or multi-layer shielding.
3) In terms of fluid, evenly distributed tiny bubbles in the measured liquid usually do not affect the normal operation of the electromagnetic flow meter, but as the bubbles increase, the output signal of the meter will fluctuate. If the bubbles are large enough to cover the entire electrode surface, As the air bubbles flow through the electrode, the electrode circuit will be momentarily disconnected, causing greater fluctuations in the output signal.
When the electromagnetic flow meters with low frequency square wave excitation measures the slurry with too much solid content, it will also generate slurry noise, which will cause the output signal to fluctuate.
When measuring mixed media, if the flow sensor is used for measurement before the mixing is not uniform, the output signal will also fluctuate.
Improper selection of the electrode material and the measured medium will also affect the normal measurement due to chemical action or polarization.
(2) Faults during the operation period Faults during the operation period are faults that occur after the intelligent electromagnetic flow meter has been debugged and operated normally for a period of time. Common faults during the operation period are generally caused by factors such as the adhesion layer on the inner wall of the flow sensor, lightning strikes, and changes in environmental conditions.
1) Adhesion layer on the inner wall of the sensor As electromagnetic flowmeters are often used to measure dirty fluids, after a period of operation, an adhesion layer will often accumulate on the inner wall of the sensor and cause failure. These failures are often caused by the conductivity of the adhesion layer being too large or too small. If the attachment is an insulating layer, the electrode circuit will be disconnected and the meter will not work normally; if the conductivity of the adhesion layer is significantly higher than that of the fluid, the electrode circuit will be short-circuited and the meter will not work normally. Therefore, the attached scaling layer in the measuring tube of the electromagnetic flowmeter should be removed in time.
2) Lightning strike Lightning strike is easy to induce high voltage and surge current in the instrument circuit, which will damage the instrument. It is mainly introduced through the power line or the excitation coil or the flow signal line between the sensor and the converter, especially from the control room power line, which accounts for the vast majority.
3) Changes in environmental conditions During commissioning, because the environmental conditions are still good (for example, there is no interference source) the flowmeter works normally, and it is often easy to ignore the installation conditions at this time (for example, the grounding is not very good). In this case, once the environmental conditions change, the operation During this period, new interference sources (such as electric welding on the pipeline near the flowmeter, large transformers installed nearby, etc.) will interfere with the normal operation of the instrument, and the output and output signals of the flowmeter will fluctuate.
Contact:
Smart electromagnetic flowmeter is a speed instrument. In addition to measuring the volume flow of general conductive liquids, it can also be used to measure the volume flow of strong corrosive liquids such as strong acids and alkalis, and uniform liquid-solid two-phase suspension liquids such as mud, ore pulp, and paper pulp. Widely used in petroleum, chemical industry, metallurgy, light textile, papermaking, environmental protection, food and other industrial sectors and municipal management, water conservancy construction, river dredging and other fields of flow measurement. Common faults, some are caused by damage to the components of the instrument itself, and some are caused by improper selection, improper installation, environmental conditions, fluid characteristics and other factors, such as display fluctuations, decreased accuracy, and even instrument damage. It can generally be divided into two types: failures that occur during installation and debugging (debugging period failures) and failures that occur during normal operation (running period failures).
(1) Faults in the debugging period Debugging is expected that faults generally appear in the stage of instrument installation and debugging. Once eliminated, they will generally not reappear under the same conditions in the future. Common failures during the commissioning period are generally caused by improper installation, environmental interference, and influence of fluid characteristics.
1) In terms of installation, it is usually caused by the incorrect installation position of the smart electromagnetic flowmeter sensor. Commonly, such as installing the sensor at the highest point of the piping system where gas is easy to accumulate; or installing it on a vertical pipe from top to bottom, there may be discharge Empty; or there is no back pressure behind the sensor, and the fluid is directly discharged into the atmosphere to form a part of the measuring tube.
2) The environmental aspect is usually mainly the interference of stray current in the pipeline, the interference of strong electromagnetic waves in the space, and the interference of the magnetic field of large motors. Pipeline stray current interference usually takes a good separate grounding protection to obtain satisfactory results, but if encountering strong stray currents such as electrolytic workshop pipelines, sometimes the peak value of the AC potential induced on the two electrodes can be as high as The flow sensor is insulated from the pipe, etc. Space electromagnetic wave interference is generally introduced through signal cables, and is usually protected by single-layer or multi-layer shielding.
3) In terms of fluid, evenly distributed tiny bubbles in the measured liquid usually do not affect the normal operation of the electromagnetic flow meter, but as the bubbles increase, the output signal of the meter will fluctuate. If the bubbles are large enough to cover the entire electrode surface, As the air bubbles flow through the electrode, the electrode circuit will be momentarily disconnected, causing greater fluctuations in the output signal.
When the electromagnetic flow meters with low frequency square wave excitation measures the slurry with too much solid content, it will also generate slurry noise, which will cause the output signal to fluctuate.
When measuring mixed media, if the flow sensor is used for measurement before the mixing is not uniform, the output signal will also fluctuate.
Improper selection of the electrode material and the measured medium will also affect the normal measurement due to chemical action or polarization.
(2) Faults during the operation period Faults during the operation period are faults that occur after the intelligent electromagnetic flow meter has been debugged and operated normally for a period of time. Common faults during the operation period are generally caused by factors such as the adhesion layer on the inner wall of the flow sensor, lightning strikes, and changes in environmental conditions.
1) Adhesion layer on the inner wall of the sensor As electromagnetic flowmeters are often used to measure dirty fluids, after a period of operation, an adhesion layer will often accumulate on the inner wall of the sensor and cause failure. These failures are often caused by the conductivity of the adhesion layer being too large or too small. If the attachment is an insulating layer, the electrode circuit will be disconnected and the meter will not work normally; if the conductivity of the adhesion layer is significantly higher than that of the fluid, the electrode circuit will be short-circuited and the meter will not work normally. Therefore, the attached scaling layer in the measuring tube of the electromagnetic flowmeter should be removed in time.
2) Lightning strike Lightning strike is easy to induce high voltage and surge current in the instrument circuit, which will damage the instrument. It is mainly introduced through the power line or the excitation coil or the flow signal line between the sensor and the converter, especially from the control room power line, which accounts for the vast majority.
3) Changes in environmental conditions During commissioning, because the environmental conditions are still good (for example, there is no interference source) the flowmeter works normally, and it is often easy to ignore the installation conditions at this time (for example, the grounding is not very good). In this case, once the environmental conditions change, the operation During this period, new interference sources (such as electric welding on the pipeline near the flowmeter, large transformers installed nearby, etc.) will interfere with the normal operation of the instrument, and the output and output signals of the flowmeter will fluctuate.
Contact:
Smart electromagnetic flowmeter is a speed instrument. In addition to measuring the volume flow of general conductive liquids, it can also be used to measure the volume flow of strong corrosive liquids such as strong acids and alkalis, and uniform liquid-solid two-phase suspension liquids such as mud, ore pulp, and paper pulp. Widely used in petroleum, chemical industry, metallurgy, light textile, papermaking, environmental protection, food and other industrial sectors and municipal management, water conservancy construction, river dredging and other fields of flow measurement. Common faults, some are caused by damage to the components of the instrument itself, and some are caused by improper selection, improper installation, environmental conditions, fluid characteristics and other factors, such as display fluctuations, decreased accuracy, and even instrument damage. It can generally be divided into two types: failures that occur during installation and debugging (debugging period failures) and failures that occur during normal operation (running period failures).
(1) Faults in the debugging period Debugging is expected that faults generally appear in the stage of instrument installation and debugging. Once eliminated, they will generally not reappear under the same conditions in the future. Common failures during the commissioning period are generally caused by improper installation, environmental interference, and influence of fluid characteristics.
1) In terms of installation, it is usually caused by the incorrect installation position of the smart electromagnetic flowmeter sensor. Commonly, such as installing the sensor at the highest point of the piping system where gas is easy to accumulate; or installing it on a vertical pipe from top to bottom, there may be discharge Empty; or there is no back pressure behind the sensor, and the fluid is directly discharged into the atmosphere to form a part of the measuring tube.
2) The environmental aspect is usually mainly the interference of stray current in the pipeline, the interference of strong electromagnetic waves in the space, and the interference of the magnetic field of large motors. Pipeline stray current interference usually takes a good separate grounding protection to obtain satisfactory results, but if encountering strong stray currents such as electrolytic workshop pipelines, sometimes the peak value of the AC potential induced on the two electrodes can be as high as The flow sensor is insulated from the pipe, etc. Space electromagnetic wave interference is generally introduced through signal cables, and is usually protected by single-layer or multi-layer shielding.
3) In terms of fluid, evenly distributed tiny bubbles in the measured liquid usually do not affect the normal operation of the electromagnetic flow meter, but as the bubbles increase, the output signal of the meter will fluctuate. If the bubbles are large enough to cover the entire electrode surface, As the air bubbles flow through the electrode, the electrode circuit will be momentarily disconnected, causing greater fluctuations in the output signal.
When the electromagnetic flow meters with low frequency square wave excitation measures the slurry with too much solid content, it will also generate slurry noise, which will cause the output signal to fluctuate.
When measuring mixed media, if the flow sensor is used for measurement before the mixing is not uniform, the output signal will also fluctuate.
Improper selection of the electrode material and the measured medium will also affect the normal measurement due to chemical action or polarization.
(2) Faults during the operation period Faults during the operation period are faults that occur after the intelligent electromagnetic flow meter has been debugged and operated normally for a period of time. Common faults during the operation period are generally caused by factors such as the adhesion layer on the inner wall of the flow sensor, lightning strikes, and changes in environmental conditions.
1) Adhesion layer on the inner wall of the sensor As electromagnetic flowmeters are often used to measure dirty fluids, after a period of operation, an adhesion layer will often accumulate on the inner wall of the sensor and cause failure. These failures are often caused by the conductivity of the adhesion layer being too large or too small. If the attachment is an insulating layer, the electrode circuit will be disconnected and the meter will not work normally; if the conductivity of the adhesion layer is significantly higher than that of the fluid, the electrode circuit will be short-circuited and the meter will not work normally. Therefore, the attached scaling layer in the measuring tube of the electromagnetic flowmeter should be removed in time.
2) Lightning strike Lightning strike is easy to induce high voltage and surge current in the instrument circuit, which will damage the instrument. It is mainly introduced through the power line or the excitation coil or the flow signal line between the sensor and the converter, especially from the control room power line, which accounts for the vast majority.
3) Changes in environmental conditions During commissioning, because the environmental conditions are still good (for example, there is no interference source) the flowmeter works normally, and it is often easy to ignore the installation conditions at this time (for example, the grounding is not very good). In this case, once the environmental conditions change, the operation During this period, new interference sources (such as electric welding on the pipeline near the flowmeter, large transformers installed nearby, etc.) will interfere with the normal operation of the instrument, and the output and output signals of the flowmeter will fluctuate.
Contact: