Ionization chambers are a less sophisticated and less accurate alternative to photo-timers, but they are also less prone to failure. This makes them the preferred choice for most current AEC systems. Prosthetic devices, such as total hip hardware, can also cause the selected ionization chamber to overexpose the image receiver. This is because the X-ray beam is absorbed into the metal of the hardware rather than exposing the ionization chamber. This is because a milliamp station is no longer selected and instead relies on ionization within the selected chambers.
An ionization chamber, also known as an ion chamber, is an electrical device that detects various types of ionizing radiation.