If an exposure results in 350,000 HU, roughly how long will the anode take to cool completely?

If an exposure results in 350,000 HU, roughly how long will the anode take to cool completely?

• A. 10 minutes
• B. 12 minutes
• C. 15 minutes
• D. 20 minutes

Answer: (C)

When an exposure deposits energy into the anode, it heats up and must dissipate that heat to return to ambient temperature. The amount of energy stored is measured in heat units (HU), and there are cooling charts that relate HU to a rough cooling time for a rotating anode. A result of 350,000 HU represents a substantial but manageable heat load, and on typical cooling charts this level corresponds to about 15 minutes for the anode to cool completely. Shorter times would leave residual heat, while a longer time would be more than necessary for this HU value. So, roughly 15 minutes is the best estimate.

When an exposure deposits energy into the anode, it heats up and must dissipate that heat to return to ambient temperature. The amount of energy stored is measured in heat units (HU), and there are cooling charts that relate HU to a rough cooling time for a rotating anode. A result of 350,000 HU represents a substantial but manageable heat load, and on typical cooling charts this level corresponds to about 15 minutes for the anode to cool completely. Shorter times would leave residual heat, while a longer time would be more than necessary for this HU value. So, roughly 15 minutes is the best estimate.