lever arm calibration

[godom]

I modified a lever arm and was trying to create a new calibration file for it.  In so doing I have been unable to successfully create a file which gives me a proper resting tension read out (i.e. close to 0.0).  Does anyone have a suggestion?

Thanks,

GO

[James-B]

Hi GO,

Where exactly are you having trouble?  Is it that the measurements are incorrect?  If so, what devices are you using and what functions are you using to acquire data from those devices?

Or does the issue lie with writing to the file?  If so, here is a link to the help document for the file I/O functions available in LabVIEW.  Let us know if you have more specific questions.

Also, I assume you are using LabVIEW; if not, please let us know what programming environment you are using.

[godom]

Yes I am using Labview to read force transmissions of mouse limb muscles or diaphragm with an aurora scientific servomotor/force transducer combination (whole mouse test system, in vitro & in situ).  Both force and length are controlled and measured with this system. Length-tension, force-velocity, force-frequency, stiffness, fatigue and work loop protocols can all be measured with this system.  After setting up the calibration in labview, I am  unable to get a "0.0" reading in the resting tension window.  I do not have an instruction manual for setting up the calibration, so I am going on intuition and word of mouth.  Basically, I hit the new force calibration window, enter masses of 0, 1, 2, 5, 20, 100, 200 grams and press test after each mass being hanged from the lever arm of the force transducer.  I then hit the calculate coefficients window, and save under a new name.  Then select this file name to use in the labview setup.  The resting tension I observed was recording at 88 mN with nothing attached to the lever arm.  I hope this helps.

[James-B]

It sounds like this has something to do with either the "calculate coefficients" function or how the LabVIEW program is using those coefficients.  I would recommend digging into that code and seeing if the calculations make sense.  If you find something you're not sure about or need clarification on coding practices, feel free to keep posting.