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
2.8/5
A basic, cheap beta-gamma counter for checking background levels and hobby samples. Buy it to learn, not for emergencies.
- GM tubeDetector
- β γ XDetects
- 132 CPM per µSv/h (Co-60)Sensitivity
- 328 µSv/hMax dose rate
Check price at Amazon$55.98
Price checked November 9, 2026. As an Amazon Associate we earn from qualifying purchases.
Pros
- The cheapest way into a GQ counter that logs to a computer
- Reads beta as well as gamma and X-rays, so it catches more than gamma-only meters
- Readings can be downloaded over USB for graphs and records
Cons
- Tops out around 328 µSv/h, so it saturates in a real emergency
- No Wi-Fi or app, so there is no live phone view or map
- No published warranty term
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-300S |
|---|---|
| Detection | |
| Detector | GM tube |
| Radiation types | β γ X |
| Sensitivity | 132 CPM per µSv/h (Co-60) |
| Max dose rate | 328 µSv/h |
| Energy range | 100 to 3,000 keV |
| Gamma spectrum | No |
| Features | |
| Data logging | Yes |
| Connection | None |
| Battery | 3.7 V rechargeable Li-ion |
Alternatives in this detector type
GQ GMC-800
A cheap, easy-to-read beta-gamma counter with a big screen and a lot of memory. Good for a first counter at home.
Amazon $85.98$85.98
GM tube132 CPM/µSv/h2,000 µSv/h
GQ GMC-320 Plus
A long-running data-logging Geiger counter for steady background monitoring at a desk. The GMC-800 costs about the same and publishes more.
Amazon $97$97
GM tube328 µSv/h
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