What is FIPS 140-2 for?
First, in a strict sense, detecting randomness by statistical tests is impossible. One can only detect absence of randomness. 

Second, a perfect compression algorithm should generate an output which is indistinguishable to random numbers. A hand-waving argument goes as follows:
If the output would not be indistinguishable from random numbers, then it would contain some remaining structure. And this structure could be used to compress the input even more.  

This means, the only thing you can probably do is to throw many good statistical tests to your random numbers. It cannot prove that your source is true random but it can give you some evidence that it is not broken.  

A third point to mention is that NIST has already superseeded the simple test of Fips 140-2 by the far more comprehensive tests of the Nist SP 800-90B publication.