01 / Story

The scene

An impulse test produces a spectacular electrical transient, but the engineering value comes from measuring it correctly. A transformer’s dielectric losses may be tiny, yet the accuracy of the loss-factor measurement can reveal a hidden problem. Partial discharge may be buried in background interference. These are different measurement challenges, and HAEFELY/TETTEX heritage includes a long documented product line for each.

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The engineering challenge

The official HiAS brochure identifies several generations of impulse analysis, from early systems through the HiAS 740, 742 and 743 to the 744. The TETTEX tan-delta family traces a separate path from precision bridges to later digital systems, including 2876, 2816, 2820, 2840 and IDAS 2823. The PD lineage has yet another genealogy, including Robinson, TE, TETTEX and DDX branches. These names are not interchangeable: they solve different measurement problems.

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Why it matters

A single vertically stacked “innovation index” would falsely imply an exponential acceleration or a direct chain between unrelated products. The correct visual is three aligned, linear timelines with original photographs where rights permit, with dated source references and explicit missing years. HAEFELY can credibly present decades of continuity in these instruments. A claim that no other firm on Earth can do so requires a global competitor survey and remains marketing language, not a proven record.

Evidence / What the documents actually establish

Sources, scope and limits.

Original impulse, tan-delta and PD brochures with historical images and model-year qualification.

  1. HAEFELY HiAS 744/744-REF official original brochure with historical model photo timelineS-F2-016 · corporate_publication · original_pdf_text_and_page2_visual
  2. HAEFELY IDAS2823/REF official brochure original visual tan-delta timelineS-F2-017 · corporate_publication · original_pdf_text_and_page2_visual
  3. Original HAEFELY Hipotronics PD lineage brochure historical chartS-F2-020 · corporate_publication · original_pdf_search_extracted_chart
  4. 40 Jahre Tettex AG, Zuerich, SEV/VSE 77 (1986) 15, 9 Aug 1986, p. 976S-167 · contemporary_reporting · 1986 full historical text retrieved via web PDF parser; PDF screenshot redirected to bot challenge, visual verification pending

Visual quotations document individual historical points with named sources and creators; they are not a general image-library licence. Equipment claims are intentionally narrower than the surrounding institution’s activities.