load cell working

[mavitrols]

Dear sir,

We are developed the new weighing conveyor using LC3 & LC1 and vision 570. we are facing the problem that our weight is not showing correct value & the fluctuation is very high. The four load cell are calibrated separately calibration is store in the eeprom. when i see the value of each load cell the loadcell connected to LC1 get fluctuated very high from negative to positive. due to that we are not able to get the correct reading. As per the sample program we use the filter & rounding FB but still the fluctuation same. We wright separate ladder for weighing but problem is as it is. please tell us the solution how i can get the stable reading.

thank

mahesh joshi

[Damian]

Most common causes of load cell fluctuations are electrical noise and mechanical stiction.

You should hang a scope probe off your bridge get an idea where the fluctuations are coming from.

Are your fluctionations seen to large time spans or short time spans?

You may have to experiment with your grounding and shielding, and try terminating at both ends, or one or the other.

What power supply are you using? Power quality issues can also work their way into the load cell readings.

[Joe Tauser]

Are you using AC or DC excitation? I've had good luck with AC.

Joe T.

[Raul]

Hi,

I have the same issue with the LC1, the loadcell manufacturer states that the shield does not need to be connected to anything. Should I try grounding the shield?