Chemical/Fixer/ Developer
What is x-ray developer?What is x-ray developer? An x-ray developer is a special solution that is used to develop latent images to visible ones in the darkroom during radiography. X-ray developer is composed of hydroquinone and phenidone (Metol). Hydroquinone is used for high contrast, while Metol is used for low contrast. During radiography, the developer is oxidized, which consequently minimizes the amount of the film's exposed silver leading to the formation of metallic silver, which is black. For the developer to work optimally, the solution to remain at a pH of 10-11. An alkali helps maintain this pH balance in the solution. Sodium sulfite is used to preserve the developer by reducing the latter's oxidation rate. Sodium sulfite also helps increase the developer's lifetime by dissolving the products into sulfonates. X-ray developer is prevented from forming fog upon acting on unexposed silver by a restrainer, potassium bromide. An x-ray developer works at an optimum temperature of (20-22 oC). When temperatures are low, one has to increase the developing time to enhance image quality and vice versa. What is x-ray developer used for? X-ray films are first placed into the developer solution during image processing. Since the developer is a reducing agent, it donates electrons to help reduce the silver bromide ionized crystals, which removes the halides and precipitates the metallic silver present in the emulsion layer. Positively charged free silver ions are attracted by the negative charge, which reduces them to black metallic atoms. It is this precipitation which corresponds to radiolucent (black color areas) on the radiograph. |