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Common Table of Geiger-Müller tubes

You can edit this page of the wiki without login to add or update the table. Just use the edit button at the top of the menu on the left.

This wiki page should serve as a common place where we can note/compare/discuss our reference conversion settings to have a more reliable data basis for our calculations and equivalencies.


Name Type A/B/G Voltage R10a Conversion Factor Compatible Notes
LND 712 Tube A/B/G 500V ? 0.00233? - -

Frieseke & Hoepfner

Name Type A/B/G Voltage R10a Conversion Factor Compatible Notes
FHZ 76V Tube -/B/G 500V ? 0.000233? Philips/VALVO 18550 1r/h
FHZ 74 Tube -/B/G 500V ? 0.00233? - 50r/h
SBM-20 0.00277
SI-180G 0.00321


2016/12/28 14:50


what do I get with the above conversion factor * count → mSv?

Do I subtract the dead time per count from the measurement time?

Can you show the calc of counts to the usual representation nSv / h?

I have the FHZ 76V tube ;-)

Grüße aus Landshut


2016/12/28 18:10

Yeah, I don't know why, but there is very little actual/credible information about it out there on the net. We've tried to collect and verify what we could and came up with convert-cpm-to-usv-h. In tests, comparing with other counters at LDR, the equivalency results were pretty much the same.

uSv/h seems to be the base for most formulas in use out there, so we've simply adopted it; other magnitudes derive from there.

When in doubt - use the source, luke:

(edr = equivalent dose rate)

Any updates, corrections and more insight are always welcome.

2016/12/31 00:19

Hi Chrono, I find a verified measuring station from “Bundesamt für Strahlenschutz” right in my area. The factor is one shift diffrent –> to µSv/h x 0.000233 or nSv/h - x 0.233 ralphi

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