Hello, new station in Belgium

Hi and welcome both to radmon.org!   (Sorry, I know I'm a little late!)

@BE_Soignies_GDK101 - That's a really neat little sensor you are using. According to the website it has an accuracy of +-10%, which is very good for measuring radiation. By comparison a SBM-20 GM tube is ~+-20%, so very much more accurate. Much less sensitive though, and I can see that by your background count of ~7.5 CPM. That will be down to the surface detection area of the sensor. I have a MGP DMC-2000 personal dosimeter and that has a similar looking sensor inside to yours. Basically a PCB with metal can over it. I suspect the sensor in my DMC-2000 is of a similar design to yours. I'd be interested in getting my hands on one to do some comparison tests, but they aren't cheap (90 euro) so I'll keep an eye out for a used one.
 

Hello,

I just had a quick look at the spec of your sensor and it is capable of reading 0.01 - 200.0 uSv/h. For contrast the Gamma Scout measures from 0.01 - 1.0 uSv/h, so if you were to detect something it would most likely show up with your sensor. You would likely get something around 1/3 of the counts of a SBM-20, but as your sensor goes as high as 200 uSv/h then it would detech in higher radiation events than the Gamma Scout, or a counter with a SBM-20, as they saturate at low levels. Despite it's lower sensitivity (which helps for higher radiation) it will work in a broader range of radiation. When a GM tube receives too much radiation it 'saturates' and will simply stop reporting. It is essentially keeping the electrical circuit around the tube a closed circuit. A bit like a dead short on the tube. So a SBM-20 will read some, some more, some more even, then nothing. Zero. Your sensor will go on much further than other sensors. This is probably due to it's pin-diode design that doesn't saturate like gas filled tubes. Probably explains it's price too.

For sources I get them from wherever I can find them. Generally ebay or more recently AliExpress for thorium type sources. Have a search on ebay for 'geiger source', 'check source', 'uranium', 'radioactive glass', 'radioactive pottery'. On AliExpress and Amazon (Amazon appears to have a larger number for sale than AliExpress at the moment) search for any mixture of the following words: negative, ion, energy, scalar, zero-point, anti-radiation, and so on. For working out if they are radioactive or not it would be best to compare with known products. I bought a massive bunch of them over some months and you can see them at the following links:

https://radmon.org/index.php/forum/radioactive-sources-and-samples/1305-radioactive-thorium-reconstituted-stone-pendant-negative-ion-energy-ju-ju
https://radmon.org/index.php/forum/radioactive-sources-and-samples/1322-more-negative-ion-energy-ju-ju-quantum-energy-pen-zero-ponit-nano-wand
https://radmon.org/index.php/forum/radioactive-sources-and-samples/1425-another-round-of-negative-ion-scalar-energy-ju-ju-sticker-bonanza
https://radmon.org/index.php/forum/radioactive-sources-and-samples/1436-latest-and-last-round-of-negative-ion-scalar-energy-ju-ju-moar-stickers

If using ebay it is worth also checking international sellers by using ebay.com instead of ebay.co.uk / ebay.de etc. as a lot are listed for international shipping, but don't appear on the localized sites. If using ebay.com it may be worth contacting the seller before purchasing to make sure they will ship to you.

I just thought, do you have an old smoke detector laying about? The older ionizing type have a small Americium 241 pellet inside the chamber. If you could carefully extract the pellet that should give your sensor something to detect. Americium 241 is mainly an alpha emitter so your sensor won't pick up on that, however the decay chain products from the Americium decaying are a gamma emitter, so you will get some clicks from the gamma rays at a short distance. Here is an instructable on obtaining one:  https://www.instructables.com/How-to-Obtain-and-Extract-Americium/

If you do try getting an Americium pellet, do be careful. Do wear appropriate PPE. If doing this for the first time then do some research into it. The pellet is a very small metal wafer with the Americium coated on one side. This wafer is then placed into the middle of the round housing piece that holds it and is pressed in by machine. Do not try and remove this, keep the whole pellet as one. Also keep out of the reach of children as it would be very easy to swallow. Handled and stored correctly low level radioactive sources are generally not an issue. And again, research before trying anything like this for the first time.