Air filter to catch radioactive particles - suggestions please

bethsalem wrote:

Is there anyone else on the Forum regularly using an air purifier to check for increases or decreases in the amount of radiation within their living and/or working enviroment?

It would be great to compare the experience of others to my own.

as of 25/10, my station "southofhobart" has been using a homemade air filter with two SBM-20s .To get a comparison, today I have set up another GC, "southofhobart3" with two SBM-20s alongside.
Let's see what happens

Previously, I've used the same filter setup logging continuously for several months alongside an SI-180g and seen some remarkable detections, even on clear days, that went totally unnoticed on the SI-180g.
What's different when compared to your situation is the fact that my readings return to normal after a day or so. Probably radon progeny.

I'm wondering if your detections represent large ammounts of 7Be (half life ~53 days), from all the recent auroral activity? Bit of a long shot I admit.
I've taken rain swabs from large sheets of glass and measured up to 16uSv. After over a week the same swabs were still far from normal so I had them tested and it turned out that 7Be was the main culprit.

I would suggest having your filter analysed.

Juzzie.

Thanks to both of your for your helpful comments.

There is a lab near Barcelona which will analyse the filter but it's very expensive to do.

I don't think it's 7 Be because the radioactivity appears to drop pretty quickly back to normal.

Juzzie, I can always post my filters for you to analyse using your gamma-spectroscopy setup!

"Juzzie, I can always post my filters for you to analyse using your gamma-spectroscopy setup!"
I don't have one but I know someone who does
I will check with him if he will test your filter and pm you his email address if he agrees.

The first significant rainfall for the last 3 months happened last night.

I tested the air purifier's two filters and overall they were a little above background, but on one corner of the inside of the pre-filter it was almost 4 times above background, averaged over 10 minutes.