About Radiation Lab
A working radiation protection engineer got tired of re-deriving the same numbers in a spreadsheet that nobody else could check. Radiation Lab is what those spreadsheets became: tools that name the standard or the model they implement, run with nothing to install, and show the assumption behind every figure.
Who writes this
Radiation Lab is built and maintained by one person, who works in the radiation field at a non-profit organisation. It is a personal project, built outside that work and funded by its author, with advertising intended to carry the running cost in future: it is not published by that organisation, carries no institutional endorsement, and the organisation is not responsible for anything here. It is not affiliated with, endorsed by, or sponsored by the IEC, the IAEA, NIST, any regulator, or any instrument manufacturer.
The tool
| The calculators | Eight tools in one calculator — point-source gamma dose rate with attenuation and buildup, beta range and bremsstrahlung, stay time and collective dose, unit conversion, decay, specific activity, detection limits, and X-ray tube spectra. Gamma constants are computed line by line from evaluated decay data and NIST mass energy-absorption coefficients rather than copied from a table, and a reference sheet for each nuclide in common use shows the result of that computation. |
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The pro workbenches
Three workbenches by the same author have sites of their own, and they come first on the home page. Field Pro characterises ISO 4037 reference X-ray and gamma fields — the tube spectrum, half-value layers, operational dose conversion and a GUM uncertainty budget, all computed in your browser. RadiMeter covers instrument metrology — how the characteristic tests of the IEC TC 45 / SC 45B standards are actually run, with a worksheet that keeps the record. M-Phreefiteq covers radionuclide transport and geochemistry for geological disposal on a PHREEQC engine. The old addresses of RadiMeter and M-Phreefiteq under this site forward to them. Since 28 October 2026 all four sites share one header, one footer and the same light and dark themes, so the menus that lead from one to another are the same everywhere.
One privacy policy and one set of terms cover radiation-lab.com and the three workbench sites. The same account works on radiation-lab.com, RadiMeter and M-Phreefiteq, but each site keeps its own sign-in, so you sign in once on each site you use; Field Pro has no account. Each tool adds a disclaimer for its own results. The calculators — disclaimer, methods. RadiMeter — disclaimer. M-Phreefiteq — disclaimer, and its own privacy and terms.
How the numbers are produced
Three rules hold across the site. Constants are computed from open data rather than quoted, so the chain from source to result stays visible. A gamma dose rate constant taken from a table is a single number whose assumptions are invisible — which photon lines were included, which low-energy cut-off was applied, which evaluation of the decay data it came from — and those choices change the answer: for Am-241, moving the cut-off from 20 keV to 10 keV raises the constant roughly eightfold. Every calculator has a methods page that states the equations, the data source and the range of validity. And a set of validation pages compares the output against worked examples and published values, so a reader can see where the tool has been checked and where it has not.
Who operates the site
Radiation Lab is an independent project operated by its author as an individual. It is not a company, and no institution reviews or approves what is published. The author writes the calculation engine, the pages and the validation reports, decides what is added and when, and is the data controller named in the privacy policy. The terms of use are governed by the laws of the Republic of Korea.
How a result is checked
Checking happens at three levels. Every calculation in the engine has automated tests, and they run on every proposed change before it is merged. The worked examples on the tool pages are pinned to the engine by those tests, so the numbers in the text are the numbers the form returns. And the validation reports work each calculation by hand from a published definition or reference value, set the result beside the tool's output, state the acceptance criterion, and count how much of the tool they cover. A report never takes its expected values from the tool's own constants, because a tool compared with itself always agrees.
Where the data comes from
Half-lives, decay modes and emission lines come from the evaluated nuclear structure and decay data published by the IAEA through its Livechart interface. Photon attenuation and energy-absorption coefficients come from the NIST tables. Unit conversions rest on their definitions in the SI and on the conversion factors published with them. Where a tool needs data that is under copyright, such as buildup factor coefficients from a paid standard, the tool takes values you supply rather than reproducing the table. The methods page names the source for each quantity.
How to get in touch
The contact page has a short form, and the same address, contact@radiation-lab.com, takes questions about the tools, corrections, privacy requests and anything else. A reply needs an email address, which the form leaves optional. Questions about the sister sites go to the same place.
What it is not
Radiation Lab is not an accredited calibration or testing laboratory, and the tools published here do not replace accredited calibration, testing, or a licensed safety assessment. A result is only as good as the data and assumptions entered into it, and remains the responsibility of the person who records it. Each tool states this in full.
It is not a substitute for measurement, for a qualified professional's judgement, or for the standards themselves. Read the terms of use for the full statement.
Corrections
If a number here is wrong, that is worth knowing and worth fixing. Send the page, the input and the value you expected to contact@radiation-lab.com.