Review on 📟 Radiation Alert RangerEXP: Advanced 2" Geiger Muller Detector with Bluetooth & Free Observer BLE App - Enhanced Radiation Detection with Protective Boot by Melvin Goerge

I have an EE background and am a keen physicist but I bought this because I like gadgets; I don't see much practical use for it unless it's WWIII. On the rare occasions when I go stone hunting or gem viewing, he will be with me. So my review is more from a consumer point of view. The processing and functionality is great. It's easy to use, the menu is intuitive. It has a speaker that clicks on each account; The speaker faces forward and can be temporarily covered with tape or your finger. Or you can just turn it off from the menu. The backlight has a 7 second timer, or you can set it to " and also acts as an alpha filter. The main unit has a plastic body and feels a little cheap, but it's functional. I don't like membrane plates - they wear out faster. The battery compartment is the worst, seems like it was added after the fact. Batteries are difficult to insert and remove and sometimes seem to break in the process. Good that the battery life is long. There is no external power supply or battery. However, the batteries work. The battery indicator only shows 3 instead of 4 bars when fully charged. I ran it on rechargeable batteries for about 100 hours and it still shows 3 bars. A wild guess is I'm getting around 300-500 hours, which is more than normal (800 hour specs with alkaline). The cable that came with it is quite rigid, so I replaced it with a 4 foot RG174 50 ohm cable. The measured values have not changed with the new cable. It's much easier to use and the extra cable foot allows the sensor to be used over the body. It comes with a nice grippy soft rubber case,