I dont know what gear you are using, but Ive never had a problem getting in wanded OR walking through an actual metal detector. The gear I have snuck in has been everything from an old Sony minidisc (2 different models), CL JB3, Edirol R09, and the Sony PCM-M10. All had no detection issues.
mics ive snuck in with those recorders were CSB's, HEB's, CA-14's. CS Battery boxes have never set them off, either.
Dont worry about it.