Geiger Counters, Radiation, Electronics, Projects and Other Good Stuff

Whilst looking around the internet I found a trove of old declassified CIA documents. Among these were one called 'Chernobyl Nuclear Power Plant Accident CIA, Department of Defense, Department of Energy, Congressional, GAO, and Foreign Press Monitoring Files' that goes into some detail about the accident from the perspective of the authorities. There was originally 4010 pages and sadly this has been shaved down to a mere 224 pages in the released document. An excerpt of this document: THE ACCIDENT According to reports filed with International Atomic Energy Agency (IAEA) on April 25, 1986,

Something I really dislike is planned obsolescence, and closely 2nd to that, where things are not user serviceable and have to be returned to the manufacturer for minor things such as battery replacement. I'm a large advocate of 'right to repair'. The battery in the Gamma Scout is a 10 year, 3.6v Lithium battery soldered directly onto the board. Gamma Scout (at last check some time ago) wanted 40 Euro plus shipping one way to Germany to replace the battery. Pfft! The original battery is about £20 all in for a replacement, but I decided to go another route and modify the Gamma Scout to take a

Well, I managed to destroy my second SBT-10A. The first destroyed itself as far as I am concerned as I took it out of it's box one day, and it was toast - post here . This one was my fault. I dropped a polarizing filter on the mica window (only from about 4cm) but it hit it and went with a proper loud bang, right in my face and showered my microscope and desk with bits of mica, then the black bits on the inside of the mica just turned to a yellow schmoo in the air atmosphere. It would have been a nice experiment had I actually planned it, but I did manage to get some video of the black

I have bought a 'PBI Microbial Air Sampler SAS Super 90' just for the simple fact it looked proper funky! I have no idea if it works, or how it works, or even exactly what it does, but bought it for shits and giggles. I paid £15. Working, they are going for about £1000! I care not for testing microbes in the air, so I figure I can make something with it. So far I have thought I can turn it into a ridiculously powerful flash light. Something around 100w LED. I could use a liquid cooler in the body, LED and smallish heatsink at the end, use the display for something, temperature, power and

There is currently Uranium Element sample - Uranyl Zinc Acetate (ZnUO2) for sale on eBay (UK) (At the time of writing 04 October 2019). I have just received mine and it gets a respectable ~2000cpm sat right next to a SBM-20. This is the same seller I have gotten Uranium dioxide (UO2yellow cake) and Uranium trioxide (UO3) from. He seems reliable and have exchanged the odd email with him. If you decide to buy you will get a small amount, about 0.5g in a small vile (as terribly pictured below...). Also please note that I have absolutely no affiliation with the seller, he is simply someone I have

I have just received my latest specimen, Autunite. It is quite fantastic! It is tiny, quite spicy and fluoresces like I have never seen before. The pictures don't do it justice as the colour is strikingly vibrant and has more of a yellow than green fluorescence. I struggled taking photos of it due to the amount of light it produces when it fluoresces. Like trying to take pictures of a light bulb! I took a few pictures with differing light levels. A selection are below. 22,000 CPM on a SBM-20 is quite spicy! Very happy with it. "Autunite (hydrated calcium uranyl phosphate), with formula

This is a list of the common radioactive sources available on ebay (at the time of writing - 31/08/2019) They vary a lot in radioactivity and I own all of these so I will try and give you my opinion of how active they are using an SBM-20 tube, in a rough, roundabout way. They will be marked 1 to 5 (5 being most active) based on the samples I own and based against each other. Where I have included the emission type (a, b & y (alpha, beta & gamma)) this is the overall emission. A lot of the different radiation types are caused from the main radionuclide decaying into other

I thought I would try and collate a good list of old and new disaster and post apocalyptic films. Below are the films I have/have watched (Some I haven't watched as yet). Nuclear disaster: The Day After (1983) Threads (1984) Chernobyl HBO miniseries (2019) The War Game (1965) Dr Strangelove (1964) Broken Arrow (1996) Chernobyl Diaries (2012) Fat Man and Little Boy (1989) The China Syndrome (1979) Biological disaster: 28 Days Later (2002) 28 Weeks Later (2007) Contagion (2011) I Am Legend (2007) World War Z (2013) Zombieland (2009) Other disaster: After Earth (2013) Independence Day

On a radmon.org forum thread we sort of got to discussing the thickness of Aluminium for shielding beta but I didn't want to divert that thread too much so started a new thread on this subject here. I had quoted, roughly in all honesty, that 5mm aluminium would do well for beta shielding and was met with this reply by user FSM19: For a beta shield you need 3mm of aluminium, foil isn't thick enough, UK Civil Defence geiger counters and ionisation instruments, such as the Meter Doserate Portable No 1 Trainer, Meter Doserate Portable No 1 and the Meter Survey Radiac No 2 had diecast bodies about

I have found a relatively inexpensive source for a Cs137 check source. It is in the form of a 'new old stock' Raytheon CK1097-15 spark gap from ebay.co.uk. (No longer listed - You may find one by searching.) It isn't very active though. I bought it to use as a calibration source for my gamma spectrometer project I'm on with. I tested using a LND712 tube and got about 55 CPM tops (background was ~17 CPM) and had to place the spark gap right up to the end window of the LND712. Whilst not very active it should work well for calibration purposes. It's hard to photo the printing on the spark gap

As the title suggests. A video by DextersTechLab on YouTube. This is well worth a watch if you are interested in scintillation. Archived from radmon.org - originally posted 18/08/2019

In reply to a nzoomed's question on radmon.org: Im wanting to build an outdoor monitoring station with an SBM20 and not sure if its good to use a PVC pipe to place the tube inside? Obviously im wanting something as thin as possible to let as many particles through as possible. Are there some materials I should avoid? Are beta particles typically encountered much in the environment? Should I only be worried about cosmic rays? Im not sure how much background radiation is from other sources, but im expecting there is a great deal from alpha decay from the likes of radon etc which will never be

Curiosity got the better of me so I decided to open up the Gamma Scout. I managed to carefully remove the sticker enough to reveal the screws so here are some pictures of the inside of the counter. The pictures aren't great as I'm not really setup with good lighting etc. A quick update after living with my Gamma Scout for a few months. Despite everything I have written (which my opinion remains true and I stand by) I have really grown to love this counter. It's very handy and just 'there' when I need/want a counter. It is the first counter I pick up now for whatever I want to check. Prior to

As the title suggests, I bought a Gamma Scout. I was, let's say, underwhelmed with it so decided to give my thoughts on it. I'll not cover everything here so if you are interested then it would be advantageous for you to read up on the Gamma Scout Alert on their website prior to reading my thoughts. I had been wanting a Gamma Scout for a couple of years to add to my collection. I'd seen them on the web, in Youtube videos. In places like Fukushima and Chernobyl/Pripyat etc. and from what I had seen I assumed, I think it's fair to say, I'd assumed it better than it actually is. I bought mine

A very strange one here. I'm looking for answers but after scouring the internet I doubt I'll find any. My SBT-10A tube has been destroyed for some reason unbeknown to myself. The mica window has completely shattered. I have no idea why. In the pictures you can see the damage. It appears that the mica has either reacted with something or it has catastrophically degraded. The last time I used this was on 20/10/2018 (so less than a month ago) when I decided to setup a reasonably controlled comparison of all my sources (I'll post about that in the future). It was working perfectly then and got

I've been working on an air quality monitor over the weekend. I have a working model that samples and logs every 5 minutes into various .csv files that are used for drawing graphs. It is a work in progress, still much to do. Take a look here: https://www.blinkyslab.co.uk/airquality/ Please ignore the data as it is not accurate as is just for testing purposes at the moment. I'll be dumping the collected data and starting from scratch when I get this into an enclosure and mounted properly outside. (All data shown on the page is good.) The hardware is very simple. An ESP8266 (Wemos D1 Mini), I2C

Blackpool UK - 19 July 2017 - Started around 17:00 BST / 16:00 UTC During quite a downpour today, 20mm in one hour. At it's peak was 65mm/h. Background radiation increased by approx 50% / 11CPM over a 2.5hour period. Not much by any means but still an indication there was some radioactive substance in the rain. Please note the Radmon graphs are UTC and the rain graphs are BST (UTC + 1) and so there is an hour difference between them. What caused it? I could be anyone's guess. Radon causing decay products to get caught up in the rain? Radioactive cloud blowing over from somewhere? Radioactive

A radmon.org user was having avalanche issues with their SBT-10 Geiger Muller tube. Doing a little research I found a little information stating that each anode on the GM tube (there is ten in total) should have it's own quenching resistor. I have mine set with a 10Mohm on each anode (see pic below) and appears to work OK, although I haven't had it running for long and just some simple tests. When I got it I scoured the web looking for info but it seems there is very little. One recurring theme was that the voltage and resistor(s) did play a very big part on getting correct counts from the

A radmon.org user posted a question asking what the black spots were in his SBT-10. I had recently bought one of these from a seller in Ukraine and mine too has the black spots similar to the one posted on radmon.org. The seller assured me that mine was NOS (new-old-stock), meaning whilst it is old, it has merely been stored for the time and never used. It appears to be working correctly regardless of it's condition. I tested each element separately and each reads around the same CPM as the others so I'm assuming that whilst cosmetically nasty, the black spots appear to do no harm. What

I have always been a little dubious about leaving radioactive test sources just laying around, although they emit small amounts of radiation. I knocked up a little lead lined box over the weekend to keep my test sources in. The box is just one of those cheapo wooden boxes from India (or somewhere) that you see for sale in markets and such that I lined with 2mm lead flashing (used above windows), painted bright orange with some paint left over from an old project. I added a label on top that is from a check source I bought from ebay and a radioactive symbol tie pin on the front. It works very