Measuring the relative density of open cell metal foams

Hello,

I would like to know how to measure the density of open cell porous iron foam. I am studying the mechanical behavior of pure iron foams for which I need to compare the relative densities of different foam samples. Could the density of the foams be simply calculated by the mass over the bulk volume (volume of the struts + volume of the pores) of the foam? Can I use Archimedes principle to calculate the foam density given that I have open cells? What is the best method to calculate the foam density? 

Best Regards,

Reza