Plant floor

Fixed hopper weigh system hunting ±3% after a load-cell swap

Rafael Quinn · Process

Four-cell hopper, new cells, same junction box. Empty cal looks fine. In auto the live weight hunts. Mechanical guys swear the hopper isn't rubbing. Analog is 4–20 into a CompactLogix. Filter? Shield? Or a cell that is fighting the others?

Imani Cole · Instrument tech
Corner test. If one corner is 10% off, the new cell isn't the same mV/V. Hunting in auto with a calm empty cal is often a pipe or flex conduit that only touches under load. Lift each connection. Analog filter in the PLC last, not first — you'll hide a mechanical rub.

Checking sign-in…