Mullard MX-124 - Unusual GM glass walled tubes

 

I have just picked up a couple of Mullard MX-124 GM tubes on ebay for a song! I originally bid a fair amount that I immediately regretted, but when the auction finished I got the for next to nothing!

There were two tubes in the auction and one came with original datasheet and Mullard guarantee . They are quite unusual in they are designed to detect radiation in liquids. Their construction is like a glass walled GM tube inside a test tube, with a stopper on the end. They are to be used in a vertical position and the liquid poured into the top of the tube and the liquid will run down to the outside of the inner glass wall of the GM tube itself. Apparently they do work but I've not tested them yet. They simply came via post about 30 minutes ago, so I'll test them in the near future. I'll probably never actually use them, but they make a nice addition to my collection.