Monitoring using spectrograms?

Haha! That's a great experiment. However, your Radiacode will pickup K-40 naturally from the background so will be hard to tell if the bananas are contributing much. Once you have the two day acquisition from the bananas, remove them, reset the spectrum and collect again for the same time period. Then you can use the 2nd background plot to take off the bananas plot and you will see if the bananas actually did increase the counts.

This image is 25.5 hours of just background from my Radiacode 101 after I re-calibrated it. It looks very similar to your bananas. To get around the small sensor size and lower sensitivity compared to larger scintillators, simply leave it for much longer so it has chance to gather those counts. I have left mine running for several days on some sources and I have got pretty good spectra with it.

On a side note, what advantages does Becquerel Monitor have over the PC Radiacode program? I find the Radiacode program does pretty much everything I need, so I'm unsure of any advantages.

 

I am going to make a new forum category - Gamma Spectroscopy. This will be for all things to do with Gamma spectroscopy. I will move this topic to that new category when I make it. I have moved this topic to the new category.

Ahh I see. I used the calibration process outlined on their website - here . I think it is in the video at the bottom of the page. The video shows K-40 being prominent in a background reading, and thus allows for a very quick way of checking calibration, probably in every spectrum gathered, unless it is noisy. It then shows how to calibrate using Thorium welding rods and setting the three peaks from the spectrum. I used a Thorium gas mantle and worked out fine for my 101. I actually used the android app to perform the actual calibration and upload the new cal values.

I've not heard of the InterSpec analysis software, so I'll take a look at that.

You have got me very curious with the banana experiment. I may have a go at it myself once my 103 is free from it's current task - I've very nearly finished a rather long experiment in producing and capturing Radon progeny and it doing the last of the sampling right now. It will be done in a day or so, so might have a look at bananas, although I don't expect to see anything more than background really. It would require a fairly controlled setup where background could be sampled for a few days, and then bananas added for exactly the same length of time, then use software to remove the background spectrum from the bananas spectrum, and see what's left! As K-40 is both a Beta and Gamma emitter, good lead shielding would be required to reduce natural K-40 background, which isn't really viable for me right now, so using the subtraction method should suffice to give an indication. I'm thinking of literally just stuffing the 103 into a bunch of bananas and see! 

Please let us see your results once you have finished yours.