This article is about radioactivity. For other uses of abbreviation, see CPM (disambiguation).
The measurement of ionizing radiation is sometimes expressed as being a rate of counts per unit time as registered by a radiation monitoring instrument, for which counts per minute (cpm) and counts per second (cps) are commonly used quantities.
Count rate measurements are associated with the detection of particles, such as alpha particles and beta particles. However, for gamma ray and X-ray dose measurements a unit such as the sievert is normally used.
Both cpm and cps are the rate of detection events registered by the measuring instrument, not the rate of emission from the source of radiation. For radioactive decay measurements it must not be confused with disintegrations per unit time (dpm), which represents the rate of atomic disintegration events at the source of the radiation.
[1]
^Cite error: The named reference knoll was invoked but never defined (see the help page).
being a rate of countsper unit time as registered by a radiation monitoring instrument, for which countsperminute (cpm) and countsper second (cps) are...
Words perminute, commonly abbreviated WPM (sometimes lowercased wpm), is a measure of words processed in a minute, often used as a measurement of the...
Actions perminute, abbreviated to APM, is a term used in video games, particularly real-time strategy and fighting games which refers to the total number...
plural 'tempos', or tempi from the Italian plural), also known as beats perminute, is the speed or pace of a given composition. In classical music, tempo...
such pulses per unit time also gives information about the intensity of the radiation. In some applications individual pulses are not counted, but rather...
measure typing and reading speeds (usually in words perminute). When converting character counts to words, a measure of 5 or 6 characters to a word is...
display on and off for longer battery life, and an infrared emitter for count verification and calibration. The voltage is derived from a separate pinned...
Such measurements are typically countsper unit time received by the detector, such as countsperminute or countsper second. Unlike the capsule source...
involved. Opponents use a cancer per dose model to assert that such activities cause several hundred cases of cancer per year, an application of the widely...
in becquerels or curies on contact. Low levels may be reported in countsperminute using a scintillation counter. In the case of low-level contamination...
dose), is the corresponding traditional unit, which is 0.01 J deposited per kg. 100 rad = 1 Gy. Equal doses of different types or energies of radiation...
standard measure of activity in units of either countsperminuteper gram of carbon (cpm/g C), or becquerels per kg (Bq/kg C, in SI units). Each measuring...
limited to a life of about 1011 count events. Additionally, the Geiger–Müller tube cannot operate above about 104 countsper second, due to dead-time effects...
dose, including absorbed dose (D) measured in: gray (Gy) energy absorbed per unit of mass (J·kg−1) Equivalent dose (H) measured in sieverts (Sv) Effective...
which is the measure of the energy deposited in matter by ionizing radiation per unit mass. Absorbed dose is used in the calculation of dose uptake in living...
used. The measurements are typically expressed in countsperminute (CPM) or disintegrations perminute (DPM). Alternatively, a solid-state, tritium-specific...
Global Information