The key to selecting an effective sweep firm involves the review of the equipment they utilize, their "documented" formal training and the depth of the real word experience they have logged.
First equipment utilized by a properly equipped service provider requires a minimum three hundred thousand dollar investment and occupies multiple steamer trunk size cases. A typical. Radio Frequency Spectrum Analyzer or X-Ray Scanner are approximately $50,000 each.
Second with respect to training, the government programs run 24 weeks in length. Far too many practitioners attended one or two "seminars" or claim they are self trained. Require proof of formal technical accreditation. The third is actual field experience. Many "experts" claim years of tenure. Ask to see their "first" training certification. If it is TSCM 101 Basics, dated one or two years ago, you should be wary !