What is the key difference in purpose between an explosimeter, a tankscope (oxygen analyzer for inert gas), and a multi-gas detector when assessing a tank atmosphere before enclosed space entry?

A. An explosimeter measures flammable gas concentration as a percentage of the Lower Explosive Limit (LEL); a tankscope/oxygen analyzer measures oxygen content (often used to confirm an inert atmosphere); a multi-gas detector typically measures several parameters together (e.g. O2, LEL, H2S, CO) to give a fuller picture before entry

B. They all measure exactly the same thing and any one instrument is sufficient

C. Only the multi-gas detector needs to be calibrated; the other instruments do not require calibration

D. The tankscope measures temperature only, the explosimeter measures humidity, and the multi-gas detector measures pressure

A. Nothing — a test lift can proceed immediately after repairs

B. The area within the grab's swing radius should be cleared of personnel before the lift

C. Testing should wait until cargo operations begin

D. Only the crane operator needs to be aware the lift is happening

A. Only the weather forecast for the next watch

B. The lunch schedule for the deck team

C. Who must remain clear of the exclusion zone while the lift takes place

D. The cargo manifest for the next port