GQ GMC-500+
The GQ to buy if you want a counter that keeps working at high dose rates. It suits emergency kits as well as everyday monitoring.
Amazon $128$128
The GQ GMC-500+ and the GQ GMC-500 are evenly matched, rated 3.2 and 3.1. The GQ GMC-500+ leads on dose-rate range. The GQ GMC-500 costs $10 less ($118 vs $128).
Prices were last checked November 9, 2026. Product prices and availability are accurate as of that date and are subject to change; the price and availability shown on Amazon or the retailer's site at the time of purchase apply. As an Amazon Associate we earn from qualifying purchases.
GQ GMC-500
A good value desk or window monitor that posts readings online over Wi-Fi. Pick the 500+ if you want readings at very high levels.
Amazon $118$118
Which should you buy?
- Choose the GQ GMC-500+ for dose-rate range (reads up to 42,500 µSv/h vs reads up to 4,250 µSv/h).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every beta-gamma geiger counters geiger counter; a clear win is highlighted. How we rank explains each one.
| Factor weight | GQ GMC-500+ | GQ GMC-500 |
|---|---|---|
| Overall rating | 3.2/5 | 3.1/5 |
| Sensitivity 25% | 22 138 CPM per µSv/h (Co-60) | 22 138 CPM per µSv/h (Co-60) |
| Radiation types 20% | 40 gamma, X-ray, beta | 40 gamma, X-ray, beta |
| Dose-rate range 15% | 88 reads up to 42,500 µSv/h | 54 reads up to 4,250 µSv/h |
| Features 15% | 70 data logging, phone or cloud connection | 70 data logging, phone or cloud connection |
| Price 15% | 73 $128 | 76 $118 |
| Warranty 10% | 0 warranty not published, scored as none | 33 1-year warranty |
Specifications
| GQ GMC-500+ | GQ GMC-500 | |
|---|---|---|
| Detection | ||
| Detector | GM tube | GM tube |
| Tube or crystal | two GM tubes (high-sensitivity and high-dose) | - |
| Radiation types | β γ X | β γ X |
| Sensitivity | 138 CPM per µSv/h (Co-60) | 138 CPM per µSv/h (Co-60) |
| Max dose rate | 42,500 µSv/h | 4,250 µSv/h |
| Gamma spectrum | No | No |
| Features | ||
| Data logging | Yes | Yes |
| Connection | Wi-Fi | Wi-Fi |
| Battery | 3.7 V rechargeable Li-ion | 3.7 V rechargeable Li-ion |
| Build | ||
| Warranty | - | 1 year |