Body Mass Measurement Device for Microgravity

I am not very familiar with the device that the astronauts use for measuring weight in microgravity.&nbsp;&nbsp;I do understand the theory, in that you measure the oscillations of a spring with a known Hooke's constant, k.&nbsp;&nbsp;This allows you to calculate the mass connected to the spring.<br><br>Does anyone know who the contractor was that built NASA's BMMD?&nbsp;&nbsp;What type of spring would be required to measure a human's weight?&nbsp;&nbsp;I'm interested in investigating this for a senio electrical engineering project.<br><br>Thanks for any help you can provide. <br><br><A HREF="mailto:kb5urq@hotmail.com">kb5urq@hotmail.com</A><br><br>Jason Dugas<br>