求幅射有關單位(包括單位轉換)及定義，意思。

The following quantities are commonly used in radiation dosimetry.

1. Absorbed dose (吸收劑量): this measures the energy deposited on organs or tissues. The unit is Gray (Gy)(戈瑞). 1 Gy = 1 J/kg

2. Equivalent dose (當量劑量): this measures the effect on human tissue or organ from different types of radiation
The unit is Sievert (Sv)(希沃特). 1 Sv = 1 Gy x (radiation weighting factor)
3. Effective dose (有效劑量): this measures the radiation effect on human taking into account the types of radiation and the sensitivity of different organs to radiation.
The unit is Sievert (Sv)(希沃特).
effective dose = equivalent dose x (tissue weighting factor)

4. Committed effective dose: this measures the accumulated dose (up to 50 or 70 years) to an indivdual from intake of radionuclides. The unit is Sievert.

5. Collective (effective) dose (集體劑量): this measures the total effective dose to a group of people or to a population. The unit is man-Sievert.

For measuring the "activity" of a radioactive substance, the unit ro be used is "Bacquerel" (Bq). 1 Bq = 1 disintegration per second.

You may refer to the web-page of the Hong Kong Observatory for more detailed information:

http://www.weather.gov.hk/education/dbcp/rad_protect/chi/r3_1.htm