Counts Per Minute - Count Rates

Count Rates

Counts per minute (cpm) is a measure of the detection rate of ionization events due to radioactivity. It is not an SI unit. It is the number of atoms in a given quantity of radioactive material that are detected by an instrument to have decayed in one minute. Counts per minute are only manifested in the reading of the measuring instrument, and are not an absolute measure of the strength of the source of radiation, which would be expressed in becquerels. Whilst an instrument can display at a rate of cpm, it does not have to detect counts for one minute, as it can infer the total per minute.

Counts per second (cps) is used for measurements when higher count rates are being encountered, or if hand held radiation survey instruments instruments are being used which are subject to faster rate changes when the instrument is moved over the survey area.

Read more about this topic:  Counts Per Minute

Famous quotes containing the words count and/or rates:

    You count your lover fair,
    your bride or your bride-groom,
    yet you would shun the room
    where their enchantments are.
    Hilda Doolittle (1886–1961)

    One of the most important findings to come out of our research is that being where you want to be is good for you. We found a very strong correlation between preferring the role you are in and well-being. The homemaker who is at home because she likes that “job,” because it meets her own desires and needs, tends to feel good about her life. The woman at work who wants to be there also rates high in well-being.
    Grace Baruch (20th century)