I have a honey well electro magnetic flow meter for brine controlled by a masoneilon 31000 series globe valve.

the meter gives a stable reading when the control valve is opened anywhere from 0-10% but opening the control valve any further causes the flow measurement to fluctuate wildly, sometimes full scale fluctuations.

I have simulated 4-20mA and I get a stable reading with no fluctuation at all.

the flow at the end of the run is a constant steady flow

I’ve done a bench test using water and the flow meter worked perfectly

I’ve installed grounding rings as the pipe is pfa lined through the whole circuit and it didn’t fix it( the pipe section of the flow meter is pp lined with hastelloy electrodes)

the flow meter doesn’t fluctuate when there is no flow , it stays on 0kg/hr which is good

I’ve noticed when looking at the measured values while in the parameters that the measured conductivity fluctuates a lot , 5000-20,000 us/cm every couple seconds. I would think the conductivity should stay the same as the liquid is being pumped in a loop and isn’t changing or mixing at all

I’ve had a vortex analog flow meter in series with The electro magnetic flow meter and the vortex meter gives a stable reading whereas the magnetic one fluctuates a lot

Ive attatched a pdf of the parameters and highlighted the changes ive made, is there something im missing?

 

Can you confirm that when you bench tested and got correct operation of the flowmeter, you were not using lined pipe?

Is the converter remote mounted or mounted on the flowtube?

If remote, is the cable connecting the flowtube to the converter factory cable or a substitute?

Is the converter AC or DC powered?

How did you wire a ground connection to the grounding rings?

Is the process charging the brine in the piping with an electrical voltage/current?

Is there an status or error code in the converter/display?

There is a reference to the use of the "virtual reference" option for PVC non-metallic pipe which is functionally the same for PFA lined pipe for a magmeter, in a field bulletin (link below) from Honeywell. It is not clear how one determines the presence or absence of a "virtural reference" option.

https://www.honeywellprocess.com/li...er TWM9000 Virtual Reference and PVC Pipe.pdf

 

Brine in a closed loop? Are you measuring sea water or some other fluid. Also, since the fluctuations begin at higher valve openiings, are you dealing with multi phase flose (air pockets, etc.).

 

I have a honey well electro magnetic flow meter for brine controlled by a masoneilon 31000 series globe valve.

the meter gives a stable reading when the control valve is opened anywhere from 0-10% but opening the control valve any further causes the flow measurement to fluctuate wildly, sometimes full scale fluctuations.

I have simulated 4-20mA and I get a stable reading with no fluctuation at all.

the flow at the end of the run is a constant steady flow

I’ve done a bench test using water and the flow meter worked perfectly

I’ve installed grounding rings as the pipe is pfa lined through the whole circuit and it didn’t fix it( the pipe section of the flow meter is pp lined with hastelloy electrodes)

the flow meter doesn’t fluctuate when there is no flow , it stays on 0kg/hr which is good

I’ve noticed when looking at the measured values while in the parameters that the measured conductivity fluctuates a lot , 5000-20,000 us/cm every couple seconds. I would think the conductivity should stay the same as the liquid is being pumped in a loop and isn’t changing or mixing at all

I’ve had a vortex analog flow meter in series with The electro magnetic flow meter and the vortex meter gives a stable reading whereas the magnetic one fluctuates a lot

Ive attatched a pdf of the parameters and highlighted the changes ive made, is there something im missing?

Looking at the attached PDF, you might want to try changing the line frequency from automatic to whatever you are using...50Hz or 60 Hz. I believe there should be a setting for that. Also check if there is a possibility to increase the field frequency from the settings. From the PDF it shows that the field frequency is at 1/6 * line frequency which is low in terms of excitation frequency. Generally dc excited mag-flowmeters utilise low frequency for stable zero output and AC excitation is used in noisy services as AC excitation provides better S/N ratio than DC excitation but at the cost of zero shift. Different OEM uses different types of coil drive technology and power and frequency. Some OEM uses dual excitation also. You might want to play with the settings a bit and check if it provides any solution. But before tweaking with all this settings it is absolutely necessary to understand that your installation and grounding should be perfect or at least according to OEM's spec and then only you should tweak with internal parameters and settings.