Search found 97 matches

by Go-Figure
16 Sep 2019, 08:34
Forum: Spectrum
Topic: Menzenschwand, Germany
Replies: 8
Views: 155

Re: Menzenschwand, Germany

I also have that peak around 90-95kev (might be offset due to poor calibration at lower energies). And I have it every time I measure something of minor activity, but it's much better pronounced when I measure higher activity samples. I don't think it's from Thorium, more like XRF of some kind, pro...
by Go-Figure
16 Sep 2019, 00:20
Forum: Spectrum
Topic: Uranocircite from Spain
Replies: 0
Views: 77

Uranocircite from Spain

Hello there, This weekend I tested a sample of Uranocircite from Andalusia, Spain. The sample is nice to look at, and shows fluorescence under UV light. So far so good. DSC06798FR.jpg DSC06805FRC.jpg DSC06825FRC.jpg As usual the Geiger counter had the first say on the activity, 536 CPM, mostly of th...
by Go-Figure
16 Sep 2019, 00:12
Forum: Spectrum
Topic: Beach sand, Vromos bay (Bulgaria)
Replies: 5
Views: 124

Re: Beach sand, Vromos bay (Bulgaria)

Interesting story, I didn'tknow anout that, thank you! It's still probably far less radioactive than the sand in beaches like Guarapari in Brazil for example, where there's Monazite sand, rich in Th232. People go there for the weekend not in spite of radioactivity, but because of that, albeit I am n...
by Go-Figure
15 Sep 2019, 23:59
Forum: Spectrum
Topic: Menzenschwand, Germany
Replies: 8
Views: 155

Re: Menzenschwand, Germany

Interesting, I can't help you with the mineral identification. I have a book about radioactive minerals but I am not an expert, so I could say something very very wrong. Yes, the spectrum is definitely U238-Ra226. In my experience it's unusual having peaks from Th234 and no X-rays from Pb214 when te...
by Go-Figure
12 Sep 2019, 20:33
Forum: Detectors
Topic: Mirion PDS 100G, Spectrometric Personal Radiation Detector
Replies: 51
Views: 1120

Re: Mirion PDS 100G, Spectrometric Personal Radiation Detector

If the peak around 1130KeV is from Protactinium-234 (1001 KeV), then there is nonlinearity and only the first half of the scale fits the calibration. Longer recording would be of coarse better, but what is your opinion on that? I also see that the HV supply is higher than the others posted above, b...
by Go-Figure
10 Sep 2019, 00:20
Forum: Detectors
Topic: Mirion PDS 100G, Spectrometric Personal Radiation Detector
Replies: 51
Views: 1120

Re: Mirion PDS 100G, Spectrometric Personal Radiation Detector

You are welcome Janni, In my experience changing the spectrum calibration has no impact at all on the dose rate, just as changing the calibration which determins the doserate doesn't have any effect on the spectrum. Anyway in order to compare CPS and doserate of two measurements the best way is to r...
by Go-Figure
09 Sep 2019, 05:50
Forum: Spectrum
Topic: Tunnel
Replies: 3
Views: 126

Re: Tunnel

were there many people at the movie? I am always wondering if there is measurably higher gammas from the K40 in a crowd of people.... The room was about half full, and the movie didn't deserve anything better than that. I wouldn't know if you can actually measure K40 contribution from people in the...
by Go-Figure
09 Sep 2019, 02:57
Forum: Detectors
Topic: Mirion PDS 100G, Spectrometric Personal Radiation Detector
Replies: 51
Views: 1120

Re: Mirion PDS 100G, Spectrometric Personal Radiation Detector

Ok guys I did the comparative test. I wanted a hot sample for this one in order to have a lot of counts and have significant results with a 999 seconds measurement. So I used the hottest sample I have, not an uranium or thorium ore, but a camera lens (you can read about the lens here , it was one of...
by Go-Figure
08 Sep 2019, 21:46
Forum: Detectors
Topic: Mirion PDS 100G, Spectrometric Personal Radiation Detector
Replies: 51
Views: 1120

Re: Mirion PDS 100G, Spectrometric Personal Radiation Detector

I post mine again since the images above for some reason are not clearly readable I see my cps per µSv/h are higher than Ciro's for Cesium, lower for Americium and the same for Cobalt. So there are two diferences going in opposite directions, hence partially compensating each other. I am not keen in...
by Go-Figure
08 Sep 2019, 17:51
Forum: Detectors
Topic: Mirion PDS 100G, Spectrometric Personal Radiation Detector
Replies: 51
Views: 1120

Re: Mirion PDS 100G, Spectrometric Personal Radiation Detector

Hi Janni, First, thanks for the photos of the inside. If two identical detectors give such different results testing the same sample one is clearly out of calibration. The only menus where you can do something about it I can think of are the ones below, which both show the same values of cps per µSv...