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GMC-800 vs GC-01

Updated: October 2026

Two amazon.co.uk listings both say beta, gamma and X-ray, and the useful differences are elsewhere. GMC-800 vs GC-01 comes down to logging, alarms, price, and the review record, not a laboratory sensitivity contest. The GQ GMC-800 is B0CKM5FJQX at £80.98, with 4.6 from 1,097 reviews. The FNIRSI GC-01 is B0F62PB6PG at £50.79, with 4.1 from 1,416 reviews. Both are on the [Geiger counter comparison](/hub/measuring-equipment/geiger-counter). Peter F. updated this page on 16 October 2026 from the GQ user guide and the FNIRSI product page. A qualifying purchase can earn us a commission at no extra cost to you. The [geiger counter buying guide](/hub/measuring-equipment/geiger-counter/sub/geiger-counter-buying-guide) holds the wider checklist.

Two amazon.co.uk listings both say beta, gamma and X-ray, and the useful differences are elsewhere. GMC-800 vs GC-01 comes down to logging, alarms, price, and the review record, not a laboratory sensitivity contest.

Our top picks

GQ GQ GMC-800

Best overall

GQ GQ GMC-800
8.6/10about £80.98
View offer
FNIRSI FNIRSI GC-01

Alternative

FNIRSI FNIRSI GC-01
8.2/10about £50.79
View offer
Soogua Soogua Geiger counter

Preis-Tipp

Soogua Soogua Geiger counter
7.6/10about £37.60
View offer
On this page
  1. 1.What both listings claim
  2. 2.Price, logging and alarms in this folder
  3. 3.What buyers reported going wrong
  4. 4.Beta sensitivity and dose-rate numbers you should not treat as settled
  5. 5.When to pick which

What both listings claim

Both bullets say beta, gamma and X-ray. Neither states alpha or a Bq/m³ radon mode. The GC-01 names a GM tube, cumulative dose from 0.00 µSv to 500.0 mSv, and 48 keV to 1.5 MeV within ±30% for caesium-137 gamma. The GMC-800 names real-time, timeframe and dosimeter functions, and says accuracy is via a design that meets US NIST and NRC standards. That NIST line is a US design sentence, not a UKAS certificate. The shared radiation line is why the titles look interchangeable. They are not, once you ask where the history goes and what failed.

Price, logging and alarms in this folder

The gap is £80.98 against £50.79, about £30. The GMC-800 states memory up to 10 years, free software, an open protocol, and a colour TFT. Alarms are LED, audio, vibration and voice. The box is the meter, a USB-C cable, a quick start guide, a safety card and a lithium-ion battery. Reviewers mention several days of battery life if the screen is not left on. The GC-01 states light, vibration and sound for current and cumulative dose. Logging is not stated in the listing. The included-components field says DSO, which does not describe a counter. If you will not use a log, part of the extra £30 buys a feature you will not use.
GQ GQ GMC-800

Testsieger

GQ GQ GMC-800
8.6/10about £80.98
View offer

What buyers reported going wrong

In 47 GMC-800 bodies, the United Kingdom review says it responded near a smoke detector and that the buyer could not vouch for accuracy. This page does not call the GMC-800 more accurate. Other buyers report scratches and image burn-in, and a sensor on the side. The GC-01's first 50 bodies include seven labelled United Kingdom. A UK buyer said a J321 tube saw a smoke detector only after a firmware change, and that the stock unit has no click until then. A UK buyer returned a unit that read far below a friend's meter. Another saw a red light and no charging after four or five days. If early failure is the risk you will not carry, skip the GC-01.

Beta sensitivity and dose-rate numbers you should not treat as settled

Do not pick a beta winner from an opened case. A sensitivity ranking would be a guess. Leave the case closed. Dose rate is unsettled too. The FNIRSI page prints both 0 to 10,000 µSv/h and 0 to 1,000 µSv/h. This page does not choose one GC-01 rate. The GMC-800 guide states 0.00 to 2,000 µSv/h, and the amazon file for B0CKM5FJQX does not, so that span is a PDF figure. Neither number is a radon result.

When to pick which

Choose the GMC-800 when you want the log and the wider alarm set and you can pay £80.98. Choose the GC-01 only when £50.79 is worth the pattern of low readings and early deaths, and you do not need a log. Neither is an alpha tool or a radon pack. Wider picks, including the Soogua as best value, are on the best geiger counter page. The background routine is on how to use a geiger counter.

Common questions

Which is more accurate?
This folder cannot say. The UK GMC-800 review would not vouch for accuracy without another meter. UK GC-01 reviews include readings far below a friend's counter. Opened-case CPM figures are not our test. Both claim beta, gamma and X-ray. Use CPM against your own background, and treat µSv/h as the maker's estimate.
Which one logs, and why is the GMC-800 dearer?
The GMC-800 logs, with memory up to 10 years, free software and a USB-C cable. The GC-01 file does not state logging. The price gap in these two files is £80.98 against £50.79. You pay about £30 for the log and the voice alarm, not for a printed dose-rate range or a UK certificate. The GMC-320S at £61.56 also logs and does not name the radiation types.
Does the GC-01 click?
Not always, as sold. A UK review says there is no click until the firmware is changed, and chip markings were removed. Silence on first switch-on can be that limit or a unit that has already failed. It is not evidence that the room has no radiation. Other buyers talk about the graph and one-handed use after the unit is working.
Do both see beta equally?
Both claim beta. They do not publish a comparison. Forum users say both cased meters are weak on beta until opened. One owner reported a large CPM rise with a GC-01 back off. That is not our measurement, and opening the case is not the advice. Tube notes mention J321, GM4011 and a smaller J614. Equal beta is unproven.
Is the NIST line a UK certificate?
No. The GMC-800 bullet says the design meets US NIST and NRC standards. That is not a certificate in the box, and it is not UKAS. The GC-01's ±30% line for caesium-137 is also a listing claim. Neither sentence makes an approved dosemeter. A test card on the FD-5000, a different row, is only a response check.
Which should I skip if units die early?
Skip the GC-01 if that pattern is unacceptable. UK reviews describe failure after four or five days, a red light with no charge, and a unit that never turned on again. The GMC-800 sample here is harsher about the screen than about sudden death. Early failure is a reason to prefer the dearer listing. It is not a claim that the GMC-800 is more accurate. Check the ASIN so you do not buy the other GMC-800 at £99 by mistake.

Related pages

Geiger counter and radon

Geiger counter

Best geiger counter: log, value pick, and who should skip

Geiger counter buying guide: tube, units and limits

How to use a geiger counter: background, then counts

Sources

UKHSA, Public Health Wales, the Health and Safety Executive and the Ionising Radiations Regulations 2017, plus manufacturer pages and the amazon.co.uk listings read on 16 October 2026. Prices move. Nothing was laboratory tested or UKAS calibrated.

  1. UKHSA, UK ionising radiation exposure, June 2025 (retrieved 16 October 2026)
  2. UKHSA, radon Action Level and Target Level (retrieved 16 October 2026)
  3. UKHSA, measuring radon (retrieved 16 October 2026)
  4. Public Health Wales, radon (retrieved 16 October 2026)
  5. HSE, ionising radiation legal base (retrieved 16 October 2026)
  6. Ionising Radiations Regulations 2017, Schedule 3 (retrieved 16 October 2026)
  7. GQ Electronics, GMC-800 user guide (retrieved 16 October 2026)
  8. FNIRSI GC-01 product page (retrieved 16 October 2026)