| Effective dose: A dosimetric quantity useful for comparing the overall health affects or irradiation of the whole body. It takes into account the absorbed doses recived by various organs and tissues and weighs them according to present knowledge of the sensitivity of each organ to radiation. It also accounts for the type of radiation and the potential for each type to inflict biological damage. The unit of effective dose is the sievert. Electromagnetic Radiation: A traveling wave motion that results from changing electric and magnetic fields. Types of electromagnetic waves include short-wave such as x-rays & gamma to ultraviolet, visible & infrared to longer wave such as radar and radio. The gamma ray photons used in a gauge to measure density is a type of electromagnetic radiation. Electron: Sub-atomic negatively charged particle with very low mass that orbits the nucleus. Element: All isotopes of an atom that contain the same number of protons. Emergency Response Sheet: A document that discusses the precautions and emergency actions pertaining to radioactive gauge during transport. An Emergency Response Sheet must be readily visible and available to the driver during transport. Similar to a Material Data Safety Sheet (MSDS). Encapsulation/Encapsulated: The shielding that encompasses a radioactive material used in a gauge. Exposure (Radiation): A measure of ionization in air caused by x-rays or gamma rays only. The unit of measure most often used is the roentgen. Exposure rate: A measure of the ionization produced in air by x-rays or gamma rays per unit of time, frequently expressed in roentgens per hour. External exposure/irradiation: An exposure received from a source of ionizing radiation outside of the body. Similar to a chest x-ray in that following exposure the individual is not radioactive. Exposure to gamma radiation from the gauge is an external exposure. | 
