The vertical channel of the force ransducers can be calibrated by use of known weights and by checking whether the output of the platform matches the weight of the weights. In addition, if the weights are applied at different points across the forceplate, the variability of the recorded force with its point of application can also be checked.

The horizontal channels of the force transduceris a little more tricky. One method involves attaching a cable to the plate surface, passing the cable over a frictionless air pulley at the level of the plate surface, and adding weights to the free end of the cable (Bartlett, 2007). However, this cannot be done with a force plate that is installed in the floor.

Hope this helps,

References that may help:

Bartlett RM (2007). Introduction to sport biomechanics (2nd ed.). Abingdon: Routledge. --> page 210

Biewener AA, & Full RJ (1992). Force platform and kinematic analysis. In Biewener AA (Ed.), Biomechanics -- structures and systems A practical approach, pp. 45–73. Oxford University.

Article Biomechanics: Structures and Systems. A Practical Approach ....

thank you very much. I was familiar to this methods and I was interested in something more realistic (in case of fixed floor platform) for the calibration of horizontal forces.

Thank you again for your help. keep in touch.

For fixed floor platform, you can use 3 pulleys.

The first is disposed at the just over the level of the floor with the cable passing under the pulley,

The second is disposed vertically above the second with the vertical cable which passes over the pulley.

The third is at the same height as the second and at a distance from the second, the cable passes over the third pulley.

The weight is attached to the end of the cable.

The cables should be as flexible as possible and pulleys with the lowest friction.

Another method is to have a force sensor attached to the ceiling by the intermediate of a turnbuckle. By turning the turnbuckle, the applied force increases and is measured by the sensor. This method eliminates the friction of the pulleys.

Thank you, but i suppose this is not standardized. Am I correct.

Maybe you know engineers, we express better in a scheme, could you please draw a schematic.

Thank you.