How can I accurately measure tension on a wire for my honours project?

[jhbroch]

Hi, I am currently doing my 4th year honours project and i am having a bit of trouble with one of the aspects of it. i have designed a test rig that simulates the motion of waves and from the test rig i have a wire leading down to an anchor point on the floor (a 5kg weight) , and i need to measure the tension on the wire. From here i plan to use a microcontroller and use fuzzy logic to control a motor which tightens/slackens the wire. I had previously thought i could place the weight on a digital scales with RS 232 output and get a varying weight output from that and then calculate tension but i don't think the output rate of the scales is sufficient. Any other suggestions? all help greatly appreciated!

James

 

[stewartcs]

I suppose you could calculate the torque the motor is developing to find the applied tension in the wire.

 

[dlgoff]

Welcome to PF jhbroch. The first thing I though of was to use a strain gauge (with electronics) to measure the tension. But the circuits involved might be a bit too much. I did some google searching but most hits were for companies selling measuring instruments.

I'm wondering if you might be able to get inside your scale, find the analog output and then hook it to an A/D to create you output?

 

[jhbroch]

hmmm i might look into that actually. and i think the strain gauge idea might be feasible too, either way i need to figure something out but at the same time not have to spend weeks doing it as i still have the programming aspect of the project too...