Load Cells connecting to PhidgetBridge Issue

[adeepdas]

I am trying to build a circular weight scale that relies on load cells to calculate the weight. I currently have the 4 load cells arranged in a cross under a circular metal sheet. Essentially, I have a load cell in each cardinal direction. Each load cell is connected to a channel on the PhidgetBridge 4-Input (SKU: 1046_0). Once I calibrate the weight scale, and try to put a weight in the North and South direction, the readings are very off with North bias reading a heavier mass and South bias reading a lighter mass. The East and West direction read fine when I bias any weights there. These load cells are connected to Channel 0 and 2 respectively.

To debug this issue, I have tried to rewire the 4-Input bridge but I consistently see that load cells connected to channel 0 and channel 2 give inaccurate readings. I also also tried a different 4-Input bridge. Does anyone have any solutions to why this might be happening?

[burley]

What load cells are you using? Not all load cells are designed to be used in a multi-load cell set up. They need to have their outputs tuned to match one another for this to work without doing manual signal trimming via an external potentiometer.

For ones that are tuned for this, you should connect all load cells to the same channel on the bridge device in parallel. That way the signals are all summed automatically for you and you just get a single reading out.