Runtime failure
After the initial commissioning and normal operation of a period of time after the operation of the failure occurred, the common causes of failure are: flow sensor inner wall adhesion layer, lightning strikes, environmental conditions change.
1, the inner wall adhesion layer
Because electromagnetic flowmeters have a much higher chance of measuring suspended solids or contaminants than other flow meters, the probability of failure due to the inner wall adhesion layer is relatively high. If the adhesion layer conductivity is similar to the liquid conductivity, the meter can still output signals normally, but only change the flow area, forming a hidden failure of the measurement error; if the high conductivity adhesion layer, the electromotive force between the electrodes will be short circuit; if the insulating adhesion layer The electrode surface is insulated and the measurement circuit is disconnected. The latter two phenomena will make the instrument unable to work.
2, lightning strike
Lightning strikes instantaneous high voltages and inrush currents in the line, which can damage the meter. There are three ways to introduce a lightning damage meter: the power line, the sensor flow signal line and the excitation line between the converter.
In view of the causes of some electromagnetic flowmeters, the company has also sorted out some installation site requirements. It is also to be able to reach the aspirational measurement accuracy, and we have stringent requirements for the choice of resettlement site. When selecting the resettlement site, the following requirements should be carefully scrutinized:
1. Electromagnetic flowmeters should be installed only if they avoid ferromagnetic objects and set up equipment with strong electromagnetic fields (such as large motors, large transformers, etc.) in order to prevent magnetic fields from affecting the sensor's magnetic field and flow signals.
2. The electromagnetic flowmeter should be installed only to prevent the sun and rain, to prevent the situation temperature is higher than 60 °C and relative humidity is greater than 95%.
3, the placement of electromagnetic flowmeter should be selected to facilitate maintenance, easy to exercise place.
4, electromagnetic flowmeter should be placed in the rear of the pump, must not be placed on the suction side; the valve should be placed on the side of the mean flow.
5, electromagnetic flowmeter should be placed only in the dry and ventilated place, should not be placed in a moist, easy to place water.
Antistatic Agent,Oleic Acid Amide,Oleamide Lubricant Agent,Cas 301-02-0
Jiangxi Zhilian New Materials Co., Ltd , https://www.zhilian163.com