Tube ratings
3 minutes
If the first exposure of the day was to heat the anode to 250,000 HU, what is the minimum time period that it will need to cool for, before you can make a second exposure of 250,000 HU?
40,000 HU
If the first exposure of the day was to heat the anode to 300,000 HU, what is the approx. amount of heat units would be measured if the anode is allowed to cool down for 6 minutes?
approx. 14 minutes
If the first exposure of the day was to heat the anode to 350,000 HU, how long would it take for it to cool down completely?
Focal Spot Size, Speed of rotation, Rectification, Repetition rate, Prep Time
Tube rating is directly affected by:
80 kVp, 300 mA, 0.04 seconds
Using this rating chart. Which from the following would be a safe exposure?
100 kVp, 200 mA for 0.15 second
which exposure is safe?
80 kVp, 200 mA for 0.2 second
which exposure is safe?
120 kVp, 200 mA, 0.2 seconds
Which from the following would be an unsafe exposure?
5 minutes
You perform two x-rays, one directly after the other. The first exposure is 150,000 HU and the second is 100,000 HU. How many minutes will it take for the anode to cool to only 50,000 HU?
Just under 100,000 HU
Your first exposure generates 250,000 HU. Three minutes later you make a second exposure of 250,000 HU. What will the heat units have dropped to after a four minute wait from the time of the second exposure?
