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
GM tube138 CPM/µSv/h42,500 µSv/h
3.1/5
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.
- GM tubeDetector
- β γ XDetects
- 138 CPM per µSv/h (Co-60)Sensitivity
- 4,250 µSv/hMax dose rate
Check price at Amazon$118
Price checked November 9, 2026. As an Amazon Associate we earn from qualifying purchases.
Pros
- Wi-Fi uploads readings to an online map with no computer attached
- Reads up to 4,250 µSv/h, far past the cheaper GQ models
- Stores readings in 1 MB of memory
Cons
- Sidewall tube misses alpha and soft beta
- Sensitivity is ordinary for a GM tube
- One-year warranty only
The GQ GMC-500 family
Every GQ GMC-500 model we rank, smallest first. Ratings compare each against its own detector type.
| Model | Detector | Rating | Price |
|---|---|---|---|
| GQ GMC-500 (this one) | GM tube | 3.1/5 | $118 |
| GQ GMC-500+ | GM tube | 3.2/5 | $128 |
How it scores
The rating comes from 6 measured or published factors, each scored 0-100 against fixed reference points for its detector type. How we rank explains each one.
Specifications
| Model number | GMC-500 |
|---|---|
| Detection | |
| Detector | GM tube |
| Radiation types | β γ X |
| Sensitivity | 138 CPM per µSv/h (Co-60) |
| Max dose rate | 4,250 µSv/h |
| Gamma spectrum | No |
| Features | |
| Data logging | Yes |
| Connection | Wi-Fi |
| Battery | 3.7 V rechargeable Li-ion |
| Build | |
| Warranty | 1 year |
Alternatives in this detector type
MOESAPU FS-5000
A cheap counter with a wide listed range for an emergency drawer. Its low sensitivity makes it a poor choice for checking samples.
Amazon $64.99$64.99
GM tube60 CPM/µSv/h50,000 µSv/h
FNIRSI GC-01
A cheap pocket Geiger counter for a curious first look at background radiation. Serious users will want more sensitivity and logging.
Amazon $51.29$51.29
GM tube80 CPM/µSv/h
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