Why EMI/EMC testing is necessary of Cryptographic Equipment? In the Book, "Endpoint Security" Page 265, It includes Electromagnetic Interference / Electromagnetic Compatibility Testing in Heading Level 1. 


Why is it necessary for Cryptographic Equipment to have EMI/EMC
Testing? 
What equipment is used to carry out such testing?
It’s my understanding that the information gained from a side channel attack would typically be isolated to the particular cryptographic algorithm’s structure, and physical hardware implementation. Provided the context of the article completing EMI/EMC testing would generally be a requirement of governing bodies like the Federal Communication Commission, which have jurisdiction even if the hardware is not running cryptographic systems. 

So in the interest of security and responsibility it would be necessary to complete this testing to ensure that the particular cryptographic software/hardware is resistant to side channel attacks, while simultaneously maintaining compliance with regard to preventing the emission/receiving of harmful EM interference. Personally completing side channel testing adds nothing to security except to gain insight on the capabilities of a potential attacker on a particular system, because even if the system being tested is resistant to side channel attacks the tester will gain zero insight into undocumented modes of operation.