Barbell Weight Measurement: Strain Gauges, Load Cells, or RFID for Microcontroller Input?

Hello,

I am conducting an experiment on measuring how much weight is on a barbell. I want to be able to feed the information into a micro controller. I have thought about using a few strain gauges or load cells attached to the barbell to measure the weight.

I have also thought about using several RFID stickers attached to the plates on the barbell that would send information to the controller telling it how much weight was on the bar.

Does anyone have any recommendations on other ways to measure the weight of the barbell?

Thanks,

Scot, those are good ways to measure the weight of the plates. Here are some other ways to do it.

One non-contact method is to view the barbell with a camera and use a PC to determine the number and size of the plates.

Another method is to electronically weigh the rack that supports the plates. As weights are removed it assumes they are placed on the bar and the bar plus plates weight is calculated.

Alternatively, proximity sensors on the bar can determine which plates are on it; the weight of each plate need not be measured as that data is already known by the system.