Help with Load Cell Selections

[TimThang]

Hey everybody!

I am currently doing a project whereby I have to build a test rig for a certain corrosion sensor. As part of this rig, I have to incorporate a real time weighing mechanism to determine the weight loss of the specimen during corrosion, and log it in a PC.

Hence, I am currently looking for a load cell that is capable of accommodating a dead weight (sensor + speciment) of between 3-5kgs. However, I still require the load cell to be able to detect a weight change of 0.1g. Does anybody know of such a load cell available? If not, does anybody have any other ideas how I can go about doing this.

Thanks!

 

[AlephZero]

I thknk the chances of finding a load cell with a resolution of 0.1g in 5kg, or 1 part of 50,000, are about zilch (at least, at a price you are likely to be able to afford).

One idea would be to counterbalance most of the dead weight. You could suspend the completel device from a spring, or design a balance beam with a counterweight. You would have to be careful about friction and protect the complete device from shocks, but buying or making a load cell to weigh a resultant unbalanced force of say 10g to an accuracy of 0.1g would be a much more feasible proposition.