If two consecutive exposures of 5,000 heat units each are performed on a 40,000 heat unit system, what is the total heat load and is cooling required between exposures?

If two consecutive exposures of 5,000 heat units each are performed on a 40,000 heat unit system, what is the total heat load and is cooling required between exposures?

• A. 10,000 total; no cooling required between exposures
• B. 5,000 total; cooling required between exposures
• C. 20,000 total; cooling required between exposures
• D. 40,000 total; cooling required after both exposures

Answer: (A)

Heat load from exposures adds up, and a tube can handle a maximum amount of heat units before cooling is required. For two exposures of 5,000 heat units each on a system rated at 40,000 heat units, the total heat load is 10,000 heat units. Since 10,000 is well below the 40,000 limit, cooling between exposures isn’t needed. Only when the cumulative heat approaches or exceeds the 40,000 threshold would cooling or a pause between exposures be necessary.

Heat load from exposures adds up, and a tube can handle a maximum amount of heat units before cooling is required. For two exposures of 5,000 heat units each on a system rated at 40,000 heat units, the total heat load is 10,000 heat units. Since 10,000 is well below the 40,000 limit, cooling between exposures isn’t needed. Only when the cumulative heat approaches or exceeds the 40,000 threshold would cooling or a pause between exposures be necessary.