Often when radon ratings are somewhere the results obtained from solid state detector like CR-39 are higher than the active detector like RAD 7 or sarad
How do you define often? Are the results often lower than the RAD 7?
Was the RAD 7 deployed the same length of time as the CR-39 and at the same time?
Both are dependent upon where they were placed and the conditions during placement.
Both have a large uncertainty distribution. It is not surprising to have the point estimate of the the radon concentration to differ more than 25% from two different devices.
The calibration of one device will be biased from the calibration of another device. A batch of CR-39 will have a mean calibration, but the batch will have a distribution in response.
Hasan - As Joseph has indicated... How often? It is pretty unusual to see good quantitative data that has the identical conditions (Rad7 and CR39). It is uncommon to see a continuous RAD7 result for a month or so - a common time for CR-39 deployment. Do you have a specific study in mind?
It is quite obvious the two should differ in the results. CR-39 gives you the results for a long time measurement but for RAD7the time of measurement is quite small in comparison to CR-39.
You must choose specific study in your mind and then can come to a better conclusion regarding this.
In my experience the Cr-39 values are often less than rad7. This could be attributed to the short half life of radon-222.
- Badges
- Science method