The historical evolution of the DC Current Transformer (DCCT)
Bibliographic record
Abstract
The DCCT (DC Current Transformer) is a measurement transformer, today a mature product, available from industry, using technologies based on the zero-flux principle. This paper retraces the history of its development as promoted in different measurement fields. There were two distinct paths of development, originating in very different requirements and objectives. The first one was for increased accuracy in testing AC current transformers resulting in the Current Comparator developed at Nikola Tesla Institute, Belgrade, Serbia and NRC, Ottawa, Canada in the end of the 1950s and beginning of the 1960s. This concept was extended to DC measurements. The second area was for the need of magnet current control and proton beam current measurements in accelerators at CERN, Geneva, Switzerland in 1961-62, later resulting in the development of the zero-flux DCCT for magnet current control in accelerators.
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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 | 0.004 | 0.005 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.004 | 0.004 |
| Science and technology studies | 0.001 | 0.008 |
| Scholarly communication | 0.006 | 0.007 |
| Open science | 0.002 | 0.003 |
| Research integrity | 0.003 | 0.004 |
| Insufficient payload (model declined to judge) | 0.006 | 0.004 |
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".