The hottest electromagnetic flowmeter has a zero d

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The electromagnetic flowmeter has a zero drift solution on site

the main components of the electromagnetic flowmeter sensor are: measuring tube, electrode, excitation coil, iron core and yoke shell. The product is mainly used to measure the volume flow of conductive liquid and slurry in closed pipelines, including acid, alkali, salt and other highly corrosive liquids. Hj-ldg electromagnetic flowmeter is widely used in petroleum, chemical industry, metallurgy, textile, food, pharmaceutical, papermaking and other industries, as well as environmental protection, municipal management, water conservancy construction and other fields

there are zero drift solutions for the electromagnetic flowmeter on site:

first, the cause of failure

the instability of the zero point of the electromagnetic flowmeter can be summarized into five causes of failure:

(1) the measuring pipeline is not full of liquid or the liquid contains bubbles

(2) subjectively, it is believed that the liquid has no flow, but actually there is a small flow; In fact, this is a misunderstanding of liquid flow conditions, rather than electromagnetic flowmeter failure

(3) the sensor is not well grounded due to external interference such as stray current

(4) causes of liquid (such as liquid conductivity uniformity and other problems)

(5) the insulation of signal circuit decreases

II. Inspection procedure

in view of the instability of the zero point of the electromagnetic flowmeter, it is necessary to make a preliminary inspection and judgment according to the overall consideration of the process, and then carry out detailed inspection and troubleshooting item by item. The sequence principle of the inspection items listed in the process is:

(1) the inspection shall be carried out in the order that the fixture is easy first and the fixture is foreign and domestic, which is very different and then difficult. The inspection items that can be observed or inquired and do not need major operations can be put in front

(2) those who will appear more frequently and have a higher probability of appearing in the future will be the first

(3) if it is confirmed through preliminary investigation that it is the cause of the last few faults, it can also be carefully checked in advance

III. fault inspection and measures

1. The pipeline is not full of liquid or there are bubbles in the liquid. This kind of fault is mainly caused by poor pipe engineering design or imperfect related equipment

2. There is micro flow in the pipeline

subjectively, there is no flow in the flow sensor, but there is actually micro flow. The main reason for this kind of failure is that the stop valve of the pipeline has poor tightness, and the small leakage detected by the electromagnetic flowmeter is mistaken for zero change or zero instability. Cases of incomplete sealing of valves due to long-term use or liquid dirt are often encountered, especially for large valves. Another common reason is forgetting to close the branch valve outside the main pipe. Sometimes, it is difficult to confirm that there is no flow in the piping system on site

3. observe whether there is leakage

4. imperfect grounding

external extension meters such as pipeline stray current mainly rely on the good grounding protection of electromagnetic flowmeter according to the interference impact of the measured object. Generally, the grounding resistance is required to be less than 10 Ω, and it is necessary to ensure that it does not share the grounding with other motors and electrical appliances. If a good environment cannot be guaranteed, the instrument will fail. Checking again at this time will bring a lot of trouble after raising funds

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