Engineering360: "Smartphone based system can measure volume of a soil sample"

Now, this would eliminate the use of the nuclear gauge used to measure moisture content and density of roadway layers. Just use a coring machine to get the sample, measure and weigh it, dry it out and weigh it again. Then, you've got the density and moisture content and that's what you need to see if it's compacted properly at the optimum moisture content. It would be a lot safer than using the nuclear machine.