Review on 📟 GQ Gamma Radiation Detection Equipment - GMC 320Plus Full Kit by Brad Ward

This is a very good Geiger counter for the price. I have used it for some low budget home experiments with small amounts of radioactive material and it has worked very well, with very stable readings both when left in the same place with background radiation and when placed next to it. to a radioactive source (sealed control source, uranium ore, a piece of depleted uranium metal weighing 2.33 g, a thorium gas shell, etc.). The battery life is excellent. I was also lucky with the software. The device records the number of readings every second in its memory, which stores data for about two weeks. The software allowed me to download the data to my computer and convert it into CSV format, which can then be analyzed in Excel to see changes in natural background radiation to determine if a very low level radioactive source is more radioactive than the background and so on. Sensitivity is a bit of an understatement and is quite dependent on where the subject is on the relatively narrow Geiger-Müller tube, which is located on the underside of the device below the keys. I have two reference sources: a sodium-22 source for testing sensitivity to gamma radiation and a thallium-204 source for beta radiation. For the beta source, I found that the plastic surrounding the GM tube prevents it from picking up the beta radiation emitted by Tl-204 (maximum energy 764 keV; advertised minimum for this device is 250 keV). If you open it up and take the source straight to the GM tube it can detect them, although you shouldn't do this with unsealed sources as they will contaminate the tube. The gamma source recorded a 2 hour average of 6032 counts per minute when the source was placed directly on the bottom of the unit with the plastic cover closed. From this I calculated an efficiency of 0.57%. It's a bit small, but it still makes the device very useful. Finally, the manufacturer has a helpful forum where you can ask questions and try to resolve any issues you may have with it, and I've heard their customer service is good, although I've never used it myself. Overall I am very satisfied and the price could not be better. Edit: Have a third sealed reference source: Manganese-54, which only emits a single 835keV gamma ray (99.98% of the time) and virtually nothing. still. The sensitivity was only about 0.30%. I think I overestimated Na-22 because it emits both a gamma ray and a positron (which produces two more gamma rays) in the vast majority of its decays. But even 0.3% is fine for most purposes, and everything else is fantastic, so I'll leave it at 5 stars.