GQ GMC-300S
A basic, cheap beta-gamma counter for checking background levels and hobby samples. Buy it to learn, not for emergencies.
Amazon $55.98$55.98
GM tube132 CPM/µSv/h328 µSv/h
2.5/5
A rugged, long-running beta-gamma survey meter for people who want an instrument-grade build. Most home users get more for the money elsewhere.
- GM tubeDetector
- β γ XDetects
- 45 CPM per µSv/h (Cs-137)Sensitivity
- 5,000 µSv/hMax dose rate
Check price at Amazon$449
Price checked November 9, 2026. As an Amazon Associate we earn from qualifying purchases.
Pros
- Runs for years on one 9 V battery
- Reads up to 5,000 µSv/h with a logging memory
- Weighs only 261 g for an instrument-grade meter
Cons
- Its sensitivity is the lowest published here
- Costs four times a GQ counter that does similar work
- GM tube is covered for only 120 days
The Mazur PRM family
Every Mazur PRM model we rank, smallest first. Ratings compare each against its own detector type.
| Model | Detector | Rating | Price |
|---|---|---|---|
| Mazur PRM-7000 (this one) | GM tube | 2.5/5 | $449 |
| Mazur PRM-9000 | Mica window GM tube | 3.1/5 | $699 |
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 | PRM-7000 |
|---|---|
| Detection | |
| Detector | GM tube |
| Tube or crystal | LND 713 |
| Radiation types | β γ X |
| Sensitivity | 45 CPM per µSv/h (Cs-137) |
| Max dose rate | 5,000 µSv/h |
| Energy range | from 35 keV |
| Gamma spectrum | No |
| Features | |
| Data logging | Yes |
| Connection | None |
| Battery | 9 V |
| Battery life | 60,000 h |
| Build | |
| Weight | 261 g |
| Warranty | 1 year |
Alternatives in this detector type
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
FNIRSI GC-03
A cheap combined radiation and EMF meter for casual checks around the house. It is not a precise radiation instrument.
Amazon $79.99$79.99
GM tube80 CPM/µSv/h
Compare
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