Durridge Inc. RAd7 monitor measures radon concentration from alpha energy spectrum.
Removing inlet filter should in principle allow to measure at least time variations in equlibrium factor, since a fraction of radon daughters is expected to be trapped in the drying column.
Anyone who tried or found literature about this? Thank you in advance for any suggestion
A drying column is a good filter. Nearly all the radon progeny will be trapped on the drying column. Removal of the inlet filter will not allow measuring variations in the equilibrium factor. The best way to measure variations in the equilibrium factor is from the face of a filter.
sure RAD7 can be used for Rn daughter as method explained by Joseph L Alvarez
As per my information, the radon-222 is alraedy measured based on the Po-218 which is 3.1 minutes. This is the reason that the meausurement protcol are usually stating no less than 15 minutes for holding time for measurement to allow equilibrium between Rn-222 and its direct daugther Po-218.
It can be measured, but one can try other alternatives available from RP&AD, Bhabha Atomic Research Center, India.
The RAD7 measures Rn-222. It measures Rn-222 indirectly by measuring Po-218 after sufficient equilibrium with Po-218 as Yasser Ebaid stated. It measures other progeny as well as Po-218 and can even be used to measure Rn-220.
The RAD7 could be used to measure the disequilibrium of Rn-222 progeny if there were no filtering and no inlet restrictions. Such a configuration would require calibration for the specific conditions (moisture, dust loading, collection time, ...). Such a configuration is not recommended as the detector and chamber will degrade and and require cleaning and recalibration, often.
The RAD7 measures Rn-222 by measuring Rn-222 progeny, but it is not designed for quantification of Rn-222 progeny.
Thank you Dr. Alvarez for giving me the answer I feared, do you know methods for continuous measuring of radon progeny, i.e. without periodical filter counting?
Francesco
You can continuously monitor using a filter and a NaI detector or a filter and a alpha detector. It is necessary to solve the decay equations for continuous monitoring if you are interested in short-term transitions. Monitoring of a moving tape filter could be useful. Periodic filter counting works. It depends upon your needs and available equipment.
- Badges
- Science topic