Building a Scale for Spaghetti Bridge Contest - Help Needed

[BuickBoy]

Hello All,

I'm currently working on a project to help with a local spaghetti bridge contest.

I'm trying to build a scale of sorts from a plate that is supported at each end. Picture a bracket "[" but with the two legs on the ground.

I'm using strain gages on the bottom in the shape of a full Wheatstone bridge. I've identified the "hot zone" of the plate by testing and comparing strain results from applying twenty pound increments from zero to one hundred sixty pounds. The "hot zone" is basically the center of the plate. (9inches by 6inches)

I'm using LabView as my tool to output the weight. Using a SC2345 module board and a SCC-SG24 module, I've got good strain numbers coming into my program. I've plotted the load vs strain in an excel spreadsheet and inserted a line of regression to get the slope of the line. This is basically to "calibrate" my scale.

I know my applied loads, and I know my strain... what do I do now to get my weight when it is not known? i.e. when 45.54lbs is applied to the scale

Thanks in advance for your help.

 

[BuickBoy]

I figured out my own problem.

I plotted my data with the strain on the Y-axis not the X-axis as I needed. Once I did that I was able to figure out the slope (3.357 in my case) and then multiply the strain by the slope which will give me my weight.

Simple algebra gets you sometimes. ;)

Thanks anyway!