Handheld geiger-counter

The Eberline ‘Monitor 4’ is an ideal entry level geiger counter for starting off in the hobby.
Here, the first photo shows it clicking away merrily while pointed at a old radium-dial clock i just happened to have laying around, you can see the geiger counter is sensitive. The radium used to make such clock and weatch dials, has not been manufactured since the 1970s –  but they are still as ‘active’ nowadays, as the half-life of radium can be a few thousand years, although the eerie green glow has long since stopped, mostly killed by the radium ironically, (unless you shine UV at them)  but i feel it may be as well to have some way of telling if something’s ‘hot or not’  its interesting, especially if you’re a science geek, and have been studying this kind of thing, like i have (since my teens)

This geiger counter is somewhat handy compared to many you will see on Ebay and here and there, insofar as it also detects Alpha particles – many dont, this counter has a grill on top to protect the sensitive mica window behind, which will allow Alpha’s in to be counted.

Common misconceptions are that geiger counters are radioactive themselves – no.  they’re not. If you’re eating brazil nuts, right now, they are more radioactive than a geiger counter is – they only *measure* things, like a multimeter does. The bright yellow ones you see on the TV and in movies are old, and are generally for high reading areas, and of little use, unless you’re very unlucky.
Just switching the thing on and it will begin clicking,  but no, its not Fukushima silver-foil hat time or time to take the living room door off its hinges, it’s natural, much of the clicks are from space, the sun to be more accurate,  but there are very slight readings all around us, from granite worktops, radon gas in cellars, tiny tiny amounts or radioactivity are even released when even burning coal, and numerous other places you wouldn’t think, it’s nothing to be worried about. Its everywhere. keep a check on it.


Above: The counter, checking an old clock..
below: the mica window, for alpha detection

mica window

All work, text and images © GB7MB

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