Nuclear Radiation Detector GQ GMC-800 Geiger Counter USA Design Product US National Standard Large Color LCD 5 Alarm Types Dosimeter Data Save & Global Share Beta Gamma X-ray Portable Device

Perfect for my needs. I wanted a good balance between price, accuracy and quality. After several days of reviewing many radiation detectors, this one kept coming up as a highly rated product for its price point. If like me you are mainly interested in having this as a preparedness tool and playing with from time to time, I would highly recommend this device.

For this review, I've uploaded my side-by-side background radiation comparison photos of this new American GQ GMC-800 Geiger Counter with the readings given by two far more expensive high-end, calibrated scintillation counters: a Thermo Radeye with external dual phosphor probe, and a Radiagem with a 2x2" NaI phosphor external gamma probe. The background readings are in a relatively high background region of Cornwall, not very far from the old South Terras Uranium Mine). Note that 300 nSv/hr = 0.3 uSv/hr, so that a GMC-800 reading of 0.3 uSv/hr is identical to the Radiagem's 300 nSv/hr. The American GMC-800 is accurate, lightweight, pocket sized and has just the features you need to rapidly check background gamma radiation. It will display counts/second, milli-Roentgens per hour (for the imperialists), uSv/hr, or counts/minute. The GMC-800's manufacturer's geiger tube gives 25 counts/second per mR/hr or per 2.5 uSv/hr (they use the RBE=1 conversion whereby 1 mR = 10 uSv). It also functions as a dosimeter, so you scroll through the options to display accumulated dose. You can also set the alarm threshold however high you like. Accuracy is within +/-20%. It comes with USB data and charge cord, a 3.7v lithium ion rechargable battery (AA sized) which is removable via a battery cover on the back, a soft dust proof case, and instructions plus radiation safety data "credit card" for a wallet, listing radiation levels and precautions needed. To turn it on, you need to hold the on/off button down for 4 seconds (probably to prevent it accidentally being turned on or off by keys or change in your pocket). The only disadvantage is that the AA sized 3.7v lithium ion battery cannot be substituted for a common AA 1.5 v battery in an emergency (it needs over 3v and won't work with a common 1.5v AA battery, I checked this). So you might want to buy a spare 3.7v lithium ion AA sized battery, or take a USB charge cable and portable phone charging power pack with you, if you want to ensure you don't run out of power. By default it makes a soft click every time a gamma ray is detected, the LED light above the display screen flashes with every "count". You can customise these settings. I have previously "tried" to buy two cheaper pocket geiger counters of other brands on Amazon, but both have been defective and been returned (I don't like reviewing totally defective products, as there's nothing to say and of course occasionally items are damaged in transit so you can't necessarily blame the product itself, which would create a misleading "review"). This American GMC-800 is brilliantly designed to do a straightforward job, does that job well, and I recommend it to anyone who needs to measure radiation.

Easy to use straight out of the box. Love the way you can have audio and vibration alerts. Portable and well made

bought this for my preppers survival collection,probably its to complicated for my use, however it covers everything so it will do the job,also I chose an american product, reason because the quality is better trusted than china tech.overall good quality,and informative instructions.

This is a true Geiger Counter in pocket size. It is fast reacting and has loud clicks and a loud alarm. It can measure Counts Per Minute, plus cumulative doses such as micro-Sieverts. It can also measure Beta as well as Gamma rays but I can’t test Alpha as they only travel a few inches in air. I use mine to check my personal outputs of Gamma rays for the first few days following Radium 223 injections where I output up to 1500CPM of Gamma and I am a potential danger to others. (The danger level for Gamma starts at about 50CPM!) This device may be useful for those whose houses are built on granite and who want to check for the hidden presence of Radon gas. I would also recommend it to anyone working with x-rays or in nuclear industries as it works faster than film badges and personal dosimeters and it has an audible alarm if safe limits are breached.

Checked with an old pre war ii watchband found that it is still radioactive.

excellent device, does exactly what it says. Various displays and measures, complete with audible 'clicks' when detecting. User replaceable rechargeable battery. Case and cable included.

I have previously owned one of the GQ300 meters and this is an upgrade. Simple and easy to use and a major improvement to the display. The measurements are broadly the same as with other GQ meters as they are using the same Geiger tube. Being fortunate and owning several other more expensive Geiger counters I have made some comparative measurements against an SEI monitor 4 (similar in size and tube size) and the GQ800 measurements were within a similar range. It is worth noting that this meter is unable to measure Alpha emissions but this is a feature of other similar tube designs that lack a mica window. For the money - yes and it comes in a handy case too.