In agencies with polygraph screening programs, polygraphers do polygraph each other, but it is little more than a formality that is necessary to keep up appearances. When polygraphing other polygraphers, either a relevant/irrelevant or directed-lie technique may be used instead of a probable-lie CQT.

As for what it takes to become a polygraph "professional" on average it's about 8 weeks and several thousand dollars:

http://www.polygraph.org/schools.htm

So I'm brand new to the site and I've got an idea that I'm sure has been thought of before but I can't seem to find it in any previous discussion.  George's tag line ("Who will polygraph the polygraphers?") got me thinking.  What does it take to become a (certified, qualified, badge-carrying, whatever) polygraph examiner?

From what I understand, a standard question that's asked at the beginning of a polygraph is "What do you know about polygraphs?".  What if one were to be able to truthfully respond "Actually, I'm a certified polygraph examiner..." etc.?  

A story is told about John Napier, a famous scientist in the 16th century.  It's said that one of his servants was stealing from him.  So, he gathered all his servants together and told them that his black rooster would tell him which servant was stealing.  The servants were each sent, alone, into a darkened room with instructions to pat the waiting rooster on the back.  Unknown to the servants, Napier had covered the rooster with lampblack.  The guilty servant, afraid that he might be discovered, was the only one to return with clean hands.  What if one of the "servants" demonstrated that they had seen this trick before? 

It seems to me that the entire "validity" for polygraph results is based solely on the assumption that this <sarcasm> fantasitc contraption, which I can never understand, can somehow read my mind and will tell the minute I'm dishonest </sarcasm>.  Candidates are usually told "whatever you know about this machine is wrong".  What if they could show that they really do know how the machine works.  What if they were in on the secret.  What if the polygrapher knew they were testing one of their own?