Electromagnetic flowmeter common failure analysis and treatment

Case introduction

　　Electromagnetic flowmeter as a precision flow measurement instrument, because of its good measurement effect for conductive liquid, in the actual industrial production

　　In the actual industrial production has been widely used. However, in the daily flow measurement, due to the existence of a variety of factors, the use of the meter head is prone to not light, the number of unstable, fluctuations, inaccurate and other faults.

　　Number of unstable, fluctuating, inaccurate and other faults. Then troubleshooting appears, we should deal with it? Let us sort out the following.

　　The meter head does not light up or yellow screen

　　1, power off and restart;

　　2, the power supply to remove other load equipment, separate power supply for the flow meter;

　　3, the scene to replace other flowmeter meter head, in order to test whether the power supply is normal;

　　4, replace the fuse;

　　5、After the above steps the fault still exists, it is necessary to return to the factory for repair.

　　There is flow through, no flow display:

　　1、Check the ‘reverse output allowed’, if it is prohibited, change to allowed;

　　2, check the air pipe alarm valve value, if the actual value is greater than the valve value, then adjust the valve value;

　　3、Close the small signal removal;

　　4, if the actual value of the empty tube alarm is too large, and the medium is conductive, then clean the electrode surface and measure the electrode path;

　　5, if the flow rate is too low, then you need to change the size of the scene, replace the smaller diameter flowmeter.

　　The number of unstable, up and down jump:

　　1, non-metallic pipe, plus grounding ring;

　　2, positive and negative bouncing number, check the ground path, such as broken, in the flange ground screws to reconnect;

　　3, check SYS, such as the excitation is not insulated or excitation line broken, try to work with a single coil, such as split, first check the junction box, the above steps can not be lifted the fault will need to return to the factory for repair;

　　4, the installation position in the ZUI high point, there are air bubbles in the pipeline, then the instrument before and after the addition of air release valve;

　　5, found that the empty tube valve value is too high, then need to clean the electrode.

　　Not allowed

　　1、4-20mA output and the meter head display can not do?

　　(1) Multimeter test the output current value of the head end, with (I-4)/16*Q/ the formula is correct;

　　(2) Whether the upper limit of the range is consistent with the nameplate;

　　(3) Check the interference around the 4-20mA output line.

　　2、Pulse output and the meter display can not be done?

　　(1) Check whether the pulse equivalent is consistent with the customer's design.

　　3, 485 can not be done?

　　(1) Send the communication protocol;

　　(2) Check the communication address in the meter head;

　　(3) Send test software to the customer.

　　No output

　　1、Current, pulse, no output

　　Remove the load, connect a multimeter to the output, and measure whether there is current and voltage. If not, change the meter head. If there is, check the telecommunication line.

　　2、No communication of GPRS

　　(1) Make a phone call next to the meter to see if the mobile phone has signal;

　　(2) Check the historical data on the platform and judge whether the battery is dead;

　　(3) Check whether the parameters of the meter head are set correctly (IP address, GPRS connection mode, communication protocol, sleep and wake up, server port number).

　　There are numbers when no flow passes

　　1, increase the small signal removal;

　　2, if you determine the pipeline medium charged, you need to add a metal grounding ring in front of the instrument;

　　3, empty pipe alarm if not open, open;

　　4, there is a strong magnetic field around but can not be removed, outside the meter set a tin box.