International comparisons of hydrophone calibrations
Bibliographic record
Abstract
In the global markets which are increasingly dominating industrial trade, international comparison of hydrophone calibrations is the primary mechanism of ensuring harmonization of underwater acoustics measurement standards across national borders. This paper describes the results of several recent comparison exercises initiated in Europe and the USA. These include both informal comparisons of hydrophone calibrations of a bilateral nature and formal comparisons involving a number of countries organized under the auspices of regional or international metrology organizations. Completed projects which will be described include a Euromet/European Commission project involving a total of 12 participants from seven European countries and a comparison between the Russian Federation and China. In these cases, results will be given and the important conclusions summarized. Finally, a relatively new comparison project will be described which has been set up under the auspices of the Consultative Committee for Acoustics, Ultrasound and Vibration (CCAUV) of the Bureau International des Poids et Mesures (BIPM) in Paris. This key comparison has now been agreed to for the kilohertz frequency range 1–500 kHz and will involve the circulation of three hydrophones. Countries participating in the comparison include the UK, China, Germany, Russian Federation, and USA, with Canada expected to join soon.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.017 | 0.045 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.003 | 0.006 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.001 | 0.003 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".