0
The original unit for measuring the amount of radioactivity was the curie (Ci)-first defined to correspond to one gram of radium-226 and more recently defined as:
1 curie = 3.7x1010 radioactive decays per second[exactly].
In the International System of Units (SI) the curie has been replaced by the becquerel (Bq), where
1 becquerel = 1 radioactive decay per second = 2.703x10-11 Ci.
The magnitude of radiation exposures is specified in terms of the radiation dose. There are two important categories of dose:
- The absorbed dose, sometimes also known as the physical dose, defined by the amount of energy deposited in a unit mass in human tissue or other media. The original unit is the rad [100 erg/g]; it is now being widely replaced by the SI unit, the gray (Gy) [1 J/kg], where 1 gray = 100 rad.
- The biological dose, sometimes also known as the dose equivalent, expressed in units of rem or, in the SI system, sievert (Sv). This dose reflects the fact that the biological damage caused by a particle depends not only on the total energy deposited but also on the rate of energy loss per unit distance traversed by the particle (or "linear energy transfer"). For example, alpha particles do much more damage per unit energy deposited than do electrons. This effect can be represented, in rough overall terms, by a quality factor, Q. Over a wide range of incident energies, Q is taken to be 1.0 for electrons (and for x-rays and gamma rays, both of which produce electrons) and 20 for alpha particles. For neutrons, the adopted quality factor varies from 5 to 20, depending on neutron energy.
The biological impact is specified by the dose equivalentH, which is the product of the absorbed dose D and the quality factor Q: H = Q D.
The unit for the dose equivalent is the rem if the absorbed dose is in rads and the sievert (Sv) if the absorbed dose is in grays. Thus, 1 Sv = 100 rem. As discussed below, 1 rem is roughly the average dose received in 3 years of exposure to natural radiation. 1 Sv is at the bottom of the range of doses that, if received over a short period of time, are likely to cause noticeable symptoms of radiation sickness.
The dose equivalent is still not the whole story. If only part of the body is irradiated, the dose must be discounted with an appropriate weighting factor if it is to reflect overall risk. The discounted dose is termed the effective dose equivalent or just the effective dose, expressed in rems or sieverts.
Radioactivity is measured using a device called a Geiger-Muller counter or a scintillation counter. These devices detect and measure the amount of radiation emitted by radioactive materials. The measurements are typically given in units such as becquerels or sieverts.
Instruments called Radiacs. There are many kinds of Radiacs, depending on the purpose they are used for. Everything from Geiger counters for instant readings of dose rate to Ionization Chambers to Dosimeters like pen and film-badge dosimeters which are to be read later for keeping individual exposure records.
There are several different units, some are:
- becquerel
- curie
- CPM
- roentgen
- RAD
- REM
- gray
- sievert
- etc.
Add your answer:
Earn +20 pts
How is digitizing used?
to measure radioactivity and to make maps
Is there a method of measuring radioactivity from a satellite or from a remote distance?
Yes, satellites equipped with sensors can measure radioactivity levels from a remote distance. These sensors can detect gamma rays emitted by radioactive materials on Earth's surface and provide valuable data for monitoring environmental radioactivity levels.
Name four instruments used to detect and measure radioactivity?
Geiger-Muller counter, scintillation detector, ionization chamber, and Cherenkov detector are common instruments used to detect and measure radioactivity. Each has its own mechanism for detecting the presence of ionizing radiation and measuring its intensity.
The derived SI unit of radioactivity named after a french physicist?
The derived SI unit of radioactivity named after a French physicist is the becquerel, symbolized as Bq. It is used to measure the rate of radioactive decay in a substance, with 1 becquerel equaling 1 decay per second. The unit honors Henri Becquerel, who discovered radioactivity in 1896.
When did Marie curie build radioactivity?
no but she built the knowleage of radioactivity.
Do you messure radioactivity in literes?
You cannot measure radioactivity in litres
What does a ginger counter measure?
radioactivity
How can one defect and measure radioactivity?
With a Geiger counter.
What does an geigercounter measure?
A geiger counter measures radioactivity.
How is digitizing used?
to measure radioactivity and to make maps
What equipment to measure radiation from sodium chloride?
The isotope 22Na is radioactive but the concentration is extremely low. A measure of the radioactivity is not necessary.
Why do you measure radioactive uranium?
The mass is measured with a balance.The radioactivity is measured with a gamma-radiometer.
Is there a method of measuring radioactivity from a satellite or from a remote distance?
Yes, satellites equipped with sensors can measure radioactivity levels from a remote distance. These sensors can detect gamma rays emitted by radioactive materials on Earth's surface and provide valuable data for monitoring environmental radioactivity levels.
Name four instruments used to detect and measure radioactivity?
Geiger-Muller counter, scintillation detector, ionization chamber, and Cherenkov detector are common instruments used to detect and measure radioactivity. Each has its own mechanism for detecting the presence of ionizing radiation and measuring its intensity.
What devices are used to detect radioactivity?
Devices such as Geiger counters, scintillation detectors, and ionization chambers are commonly used to detect radioactivity. These devices can detect the presence and measure the strength of radiation from radioactive materials.
What measuring tool do you use for an apple?
pH meter to measure the acidityruler or caliper for linear dimensionstape measure for the circumferencescale for the masscolorimeter for the hue or colorthermometer for the temperatureGeiger meter for the radioactivity...
Can you tell what happens in certain intervals of time?
Short answer: Yes, through observation you can tell what happens in a given interval of time.Long answer: It is not possible to measure everythingthat happens in a given interval of time, but only atomic (individual) changes. For instance, if you wanted to measure radioactive decay over a period of time, you would measure the amount of radioactivity at a starting point, measure a set amount of time passing then measure the level of radioactivity at the end. Subtracting the last measured radioactivity from the initial measurement will give you the amount of radioactive decay. In a simpler example, you could measure your height on January 1st of 2012, then again on January 1st of 2013 to see how your height has changed over the course of one year.
