This is an official ODERSA website. Here’s how you know

The official domain

The address of this site ends in odersa.org. Every service the association runs sits on a subdomain of odersa.org and nowhere else. If the address in your browser’s address bar does not end in odersa.org, this site is not ours.

Free, and no account

Everything is open straight away. No sign-up, no account, no password, no subscription, no advertising. Nothing is held back for those who pay, because there is nothing to pay for.

No data collected

This site does not follow you: no tracker, no tracking cookie, no measurement tool built into these pages, and nothing measured on your device. Our host counts requests in aggregate, as any server that answers does: a total, never a profile. You do not have to take our word for it: open your browser’s developer tools, go to the Network tab, and reload the page. You will see the full list of what the site asks for. Everything comes from odersa.org, nothing goes anywhere else.

Free to reuse

The content is published under the CC BY 4.0 licence. You may copy it, translate it, print it and pass it on, for your classes as much as for the people around you, on one condition only: credit ODERSA.

Research notes

The division’s notes

Texts longer than news entries: notes on method, readings of measurements, commented figures. Each note is dated, rests on published readings, and can be re-read like the rest of the site – without taking anyone’s word for it.

2026

  • Note 2026-01 – A verifier that knows how to fail. A reading of the measurement campaign: why a check that finds nothing proves nothing by itself, and what the instrument’s calibration – in both directions – makes readable.

A note gets written when a measurement, a figure or a question of method needs more room than the News page gives; nothing is written here to fill space.

The rule of the notes

A note rests on a published reading

It reads measurements, comments figures, sets out a method. It never describes the system’s internal procedures, and promises nothing the site does not prove.

Signature: ODERSA Research · CC BY 4.0 licence.

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