To improve communication efficiency with after-sales personnel, as a field instrument technician, what homework can we do before contacting and communicating with after-sales personnel for different fault situations? Below, ELETTA brings you some practical information on troubleshooting electromagnetic flow meters. Let's learn it quickly!

　　I. The meter head does not light up or shows a yellow screen

　　1. Determine whether it was used normally before the fault occurred. The purpose is to help after-sales personnel determine whether the instrument was damaged before leaving the factory;

　　2. Check whether the fuse is intact. The purpose is to check whether the fuse was damaged during the power connection process;

　　3. Check whether the terminals and voltage are correct, and ensure that the power cord is connected according to the instructions;

　　4. Use a multimeter to measure the input voltage of the meter head power terminals to rule out faults caused by unstable voltage;

　　5. Verify the number of power load devices to rule out voltage drop caused by voltage division;

　　6. Check the meter head circuit board for obvious burnt black marks? Are the capacitors exploded? Take photos of the circuit board and send them to the after-sales personnel to rule out the possibility of high-voltage breakdown;

　　7. Take clear photos of the circuit board and send them to the after-sales personnel to facilitate the after-sales personnel's preliminary judgment of the solder joint path and facilitate subsequent voltage detection, etc.

　　II. Flow is passing through but no flow is displayed

　　1. Determine the daily average or historical instantaneous flow rate, that is, the empirical flow rate, and accurately state it to the after-sales personnel. The purpose is to help the after-sales personnel rule out the situation where the on-site flow rate is lower than the lower limit of the instrument flow rate;

　　2. Inform the after-sales personnel of the measured medium to help them determine whether the instrument is suitable for electromagnetic flow meter measurement and rule out the situation of non-conductive media;

　　3. Check whether the valves before and after are fully opened to rule out the situation where the instrument does not display flow due to operational errors;

　　4. Are there FGP or SYS alarm indicators (small bells) on the meter head? Check for empty pipes; enter the measurement interface menu, find MTP, enter the parameter settings according to the actual MTP, find the empty pipe alarm threshold, and set the empty pipe alarm threshold 300 higher than MTP

　　5. Is the height of the outlet end of the flow meter installation position higher than the inlet end? Check for incomplete pipe filling due to incorrect installation.

　　III. Unstable reading, jumping up and down

　　1. Inform the after-sales personnel of the pipe material at the installation site, whether it is plastic or metal, to help them check whether there is a situation where non-metallic pipes are not grounded;

　　2. Check whether there is an installed grounding ring and the grounding situation. If necessary, take photos and send them to the after-sales personnel to help them determine whether there is a grounding ring problem;

　　3. Inform whether it has been running normally before, to help after-sales personnel determine whether there is a factory problem;

　　4. Inform the measured medium to rule out electrode problems caused by the medium;

　　5. Clearly state the fluctuation range, from zero to positive, or from negative to positive, to further determine whether it is caused by poor grounding leading to unstable fluid, or damage to the excitation leading to large-range jumping numbers;

　　6. Check the meter head for excitation alarm display to rule out unstable readings caused by water immersion;

　　7. Check whether the ground wire and grounding screw are conductive to rule out the situation where the ground wire is broken;

　　8. Take photos of the installation location and the direction of the medium flow to facilitate the after-sales personnel to rule out whether the instrument reading is unstable due to the installation location.

　　IV. Inaccurate

　　1. Clarify whether it is too large or too small to facilitate judgment by after-sales personnel;

　　2. Clarify the theoretical flow rate and the actual flow rate, respectively, to rule out the situation where the flow rate is below the lower limit;

　　4. Clarify whether the display is inaccurate or the output is inaccurate to rule out information output problems;

　　5. Clarify whether the pipe is a plastic pipe and whether the lack of grounding causes inaccuracy;

　　6. Whether the flow meter is installed at the highest point to rule out the situation of incomplete pipe filling. If necessary, take photos on site to facilitate communication with after-sales personnel;

　　7. Clarify whether it is vertically installed and the direction of the medium flow to rule out the situation of incomplete pipe filling.

　　V. No output

　　1. Clarify what the output method is? Is it current, 485, pulse, or GPRS wireless;

　　2. Does the meter head have an instantaneous value display? If not, refer to the handling method for flow passing through but no display to help after-sales personnel determine whether it is a meter problem or an output module problem;

　　3. No current output: After removing the load, check whether there is DC current between the IOUT and COMM terminals of the meter head;

　　4. No pulse output: After removing the load, check whether there is direct voltage between the POUT and COMM terminals of the meter head;

　　5. No 485 output:

　　(1) Check whether the "communication address" parameter in the meter head is correct;

　　(2) Check whether the data address in the communication protocol is correct;

　　(3) Test with the 485 test software provided by the manufacturer to see if it is normal;

　　6. GPRS:

　　(1) Clarify the time and date of the last successful communication;

　　(2) Clarify whether the antenna part at the installation site is covered by water;

　　(3) Clarify whether the antenna location is under an iron manhole cover;

　　4) Clarify whether there is a mobile phone signal underground to determine whether no output is caused by no signal;

　　(5) Check whether the parameter settings meet the requirements.