🔬 GQ 600Plus Radiation Detector Dosimeter: Your Ultimate Radiation Detection Solution Review

The GMC-600 plus is a very good geiger counter. It has a 2" LND 7137 pancake tube which is the most sensitive 2" tube I know of. A tube costs $200. This tube is sensitive to alpha radiation as well as the beta and gamma radiation common to most Geiger tubes. The battery lasts forever (days). I pinged it for accuracy as the 10 and 15 second averaging modes appear to be buggy and GQ support has not responded to multiple requests for access to a firmware update that exists based on their own…

I've had mine for a few months now. I got it more out of curiosity than anything. It works well and the battery life is great. Keeping an eye on the background, I'm checking an old Pentax lens that I know has a radioactive back element. Many older lenses from the 1940s to 1970s used thorium oxide. It's amazing how much radiation the rear element emits on its surface. The lens above measures 250 CPM at the front element and approximately 130 CPM behind the camera when the lens is attached to it.

Works well up to 22,000 samples, then the device starts to see an unreasonable jump in samples around 100,000 and the device responds after that no longer removed from the test source through still reads. The samples are sealed in epoxy resin, sealed in a plastic bag, the blocks are not contaminated, after restart they will return to normal. Sample scan crashes again. Not impressed as the device is rated for 1 million pulses per minute. I'm not sure if this is normal for the device, but I hope…