Really very strange, the company has no calibration data of your own product? I recommend that you talk directly with someone (sales representative or technical department responsible) in this company. Unfortunately, I don't know this force platform model, and I didn't find any specification about it. There is another possibilty, maybe this platform model have been placed (only the comercial name), so, the specifications (global caractheristics) can be same of the new model. Sometimes its a common pratic that occur in this entreprises. Have you checked this possibility?
Thank you for your answer. I checked these possibilities.The company (sales and technical dept.) don't have the calibration data. We own the new model of the force plate, but it has not the same data. We checked it with the same weight and the differnce is 200 Newton.