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Bill's class
Unit 2 lessons 16-19
| Question | Answer |
|---|---|
| What is voltage | Electrical unit of measurement |
| How is kvp realated to the energy of the beam | It is directly related |
| How is kvp related to optical density | it is directly related |
| What should kvp be used to control | Radiographic contrast |
| If the space charge compensator is working properly, what property of the primary beam is affected by kvp | Energy, penetrating power, and quality |
| What is beam divergence | As the primary beam travels it spreads apart |
| What is the geometric shape of the primary beam | Cone |
| Why is the primary beam cone shaped | Beam divergence |
| What is photon density | The compactness of the photons at a given distance |
| As SID is increased what happens to photon density | It is reduced |
| What is the relationship between the SID and optical density | they are inversely proportional |
| What is the inverse square law | Intensity is inversely proportional to the square of the distance |
| What is the formula for the inverse square law | I1/I2=(SID2/SID1)^2 |
| What is the purpose of film development | convert a latent image to a manifest image |
| Can a properly exposed film be over-developed, explain | No, futher increase in optical density beyond normal processing time is due to development fog activity |
| During manual development what is considered "ideal" development time | 5 minutes |
| Why are the images that are developed under five minutes lighter in optical density | They have not been fully developed (underdeveloped) |
| How is development time related to optical density | directly related |
| What is a latent image | Invisible image, has not been developed |
| What is a manifest image | Visible image, after it has been developed |
| How is temperature of the developer related to optical density | directly related |
| What is chemical fog | Image that is fogged due to development |
| What are three ways that a film can be fogged by action of developer | Developed to long, developed to hot, or contamination |
| How is developer temerature controlled in an automatic processor | Thermastat |
| During automatic development what is the maximum temperature latitude | +-0.5*F |