Originally Posted by
Boggie Dog
I don't know if TSA uses a different ETD system than the rest of the world but the system used by TSA is plagued with false alarms. My definition of a false alarm is when the system alerts and no contraband is found. Perhaps this is caused by operator error, reusing test swabs, improper storage of test swabs, calibration, or detection thresholds settings. In my opinion when a test system of any kind alarms, no positive reason for that alarm is identified, then the testing system is suspect and near worthless.
The problems TSA have are manifold. 1. They don't train their testers well. 2. The testers don't adhere to the minimal and incorrectly directed training they do get. 3. TSA doesn't service their equipment properly. Or possibly at all. 4. Their testing regime is not designed to surface actual threats. Even if they were managing the mass screening via statistical risk modelling they wouldn't be using it as often as they do. It is literally no more than security theatre.
There *is* a role for trace testing. There's even a role for random trace testing - if you're that paranoid. But there is no role for random trace testing in a mass transit system other than to slow the system, and there is even less of a role when the testing is done poorly on badly maintained machines by people who don't understand what it is they're actually doing. Trace testing (like body scanners) should be used as a secondary protocol when indicated during a secondary screening.