Sievert equal

Sievert (Sv)—The SI unit of any of the quantities expressed as dose equivalent. The dose equivalent in sieverts is equal to the absorbed dose, in gray, multiplied by the quality factor (1 sievert equals 100 rem). 

Dose Equivalent (DE)—A quantity used in radiation safety practice to account for the relative biological effectiveness of the several types of radiation. It expresses all radiations on a common scale for calculating the effective absorbed dose. It is defined as the product of the absorbed dose in rad and certain modifying factors. (The unit of dose equivalent is the rem. In SI units, the dose equivalent is the sievert, which equals 100 rem.)... 

Rem—A unit of dose equivalent that is used in the regulatory, administrative, and engineering design aspects of radiation safety practice. The dose equivalent in rem is numerically equal to the absorbed dose in rad multiplied by the quality factor (1 rem is equal to 0.01 sievert). 

Absorbed dose in rad equal to 1 rem or the absorbed dose in gray equal to 1 sievert. 

A unit of dose equal to the amount of ionizing radiation that produces in humans the same biological effect as one rad of X-rays or gamma rays. One rem is equal to 0.01 sievert. 

Sievert Sv Dose equivalent, equal to dose in Gy multiplied by quality factor (unity for X, y and fi rays, 10 for neutrons, 20 for a particles)... 

Note. Since the quality factor is unity for external gamma and for irradiation of the thyroid, Sieverts and Grays are equal numerically. 

Different types of radiation affect biological materials in different ways, so a different unit is needed to describe the dose necessary to produce an equivalent biological damage. Historically, this unit is the rem (roentgen-equivalent-man). The dose in rem is equal to the dose in rad multiplied by a quality factor, which varies with the type of radiation. For )3 -, y-, and X-ray radiation, the quality factor is 1 for neutrons, it is 2-11, depending upon the energy of the particle and for a-particles, the quality factor is 20. The SI unit for equivalent dose is the sievert (Sv), which is equivalent to 100 rem. 

Sievert (Sv). The international unit of dose equivalent and equal to 100 rem. 

Dj is the absorbed dose averaged over the tissue organ T, due to radiation R. Hj is measured in sieverts (Sv) 1 Sv = 1 J kg. The earlier, but similar concept was the rent (radiation equivalent man), where 1 Sv equaled 100 rem. Until 1990, Hj was called dose equivalent. Dj is measured in the units of gray (Gy). The summation is taken over all sources irradiating the target. 

The estimated 50-year dose commitment from plutonium for people in the north temperate zone due to atmospheric tests conducted before 1973 is 0.2 mrad (0.002 mGy) to the bone lining cells (Eisenbud 1987). [The gray is an SI unit of absorbed dose and is equal to 0.01 ram.] The average annual dose equivalent from all background radiation to an individual residing in the United States is estimated to be 360 mrem (3.6 mSv) (NCRP 1987). [The sievert is an SI unit of dose equivalent and is equal to 0.01 rem.]... 

Radiation doses that people receive are measured in units called rem or sieven. (One sievert is equal to 100 rem.) Scientists estimate that the average person in the United States receives a dose of about one-third of a rem per year. 

When the pressure is relatively low, the diffusion is assumed to be the rate-limiting step and the factor n is equal to 0.5. In this case, Eq. 2.2 becomes the Sieverts-Fick law [36] ... 

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