Explosives Trace Detection and Alarm Resolution Flashcards

A passenger alarms ETD and says they take nitroglycerin for a heart condition. How should the officer treat this information?

Answer: As a possible explanation that still requires full alarm resolution

Medications such as nitroglycerin can cause alarms, but the officer must still complete the required resolution steps rather than relying on the passenger's explanation.

Why must an ETD sample swab not be reused after it alarms?

Answer: It may now carry residue that contaminates later samples

An alarmed swab may hold detectable residue, so reusing it could cause false alarms on other people or items.

What does an ETD 'alarm' mean?

Answer: The unit detected a substance matching a programmed threat signature

An alarm means a substance matched a threat profile above the detection threshold; it calls for resolution but does not prove a threat exists.

Which passenger activity is a well-known innocent source of ETD alarms on hands or clothing?

Answer: Handling certain fertilizers or gardening products

Some fertilizers contain nitrate compounds that can leave residue detectable by ETD.

If an ETD unit shows a fault or fails its verification check, what should the officer do?

Answer: Take it out of service and report it according to procedures

Equipment that fails verification can't be trusted and must be taken out of service until it is repaired or verified.

While resolving an ETD alarm on a bag, why should the passenger keep the bag in view but not touch it?

Answer: It keeps the screening intact while respecting the passenger's interest in their property

Keeping the passenger nearby and in view without letting them handle the bag protects the screening and lets them watch their belongings.

What is the main reason ETD sampling happens on a clean, designated surface?

Answer: To reduce the chance of contamination affecting results

A clean, designated sampling area cuts down on stray residue that could cause false alarms or unreliable results.