DollaTek Nuclear Radiation Detector Personendosimeter Röntgenstraler, Straling, Straling, Radioactiviteitstester, Marmeren Detector

I low cost monitor like this will probably not have the accuracy of something costing £3000. However it goes up a bit with a small increase in radiation (a low dose DEXA xray machine at 2 metres distance caused a x10 background increase) and goes up a lot more as the radiation level increases. I am sure it will probably notice if anything fishy happens out in the world. Battery lasts less than a day continuous use but works indefinately plugged in via usb.

Seems ok, difficult to know if its working correctly but it does increase the readings when a banana is placed close to it, the potassium is registered as an increase in radio activity. Suppose we will find out if porky or Ivan really start losing it.

The GM tube fitted is the small 50mm long stainless steel cathode J613 which is only capable of detecting Gama and X rays and can't detect Beta particles. Fitted in this product it only reads about 1/3 of the background radiation present too.However purchasing a genuine J321 90mm long GM tube which the unit was originally designed for restores performance with the correct background radiation measured. The J321 has a metallised glass coated cathode and is capable of detecting Beta particles along with Gama and X rays. A slight adjustment of the voltage is required to bring it to under the maximum tube rating of 600V by adding a missing 50 Meg Ohm resistor to the PCB which was also on the original design.With the genuine J321 tube the unit performs well, although in standard form there are no "clicks" only LED flashes - however a small circuit modification (N type MOSFET addition) can be made to link the loudspeaker to the LED circuit so the flashes are accompanied by an audible click.Runtime appears to be around 10 hours with the battery only taking about 800 mAh charge accumulation despite being marked 1100 mAh. It is possible to fit a larger Lithium Polymer battery.There seems to be a bug in the firmware that incorrectly counts about 1/3 of the "Accumulated stored" dose reading when compared to the live average.Apart from that it's a great little unit when modified with the original specified J321 tube and with added clicks. So, I've only rated it one star but would have rated it as four star if I didn't need to do the work. Thanks to Studio 326's work in identifying the GM tube issues and restoring and improving performance.

Fine

Really insensitive to all bands of it’s specified radiation detection, checked & verified against several devices from the inexpensive to professional.Some people have reported the same issue as well, with the possibility of later units unit not being fitted with the correct J321 GM tube of earlier examples for which it was designed.I could take it apart myself on the bench to diagnose the problem, but why waste my own time when it should be calibrated from the factory.Beware..