unknownsynthetic
evidence: unknown
no source states which grade this article was bought at — this row exists so 'unknown' stays countable instead of becoming an assumption
exec:bifora-91/unknown
accepteddisputed
movement
Bifora 91
bounding evidence — no range is drawn on the era axis
not after 1965
a dated example movement, ca. 1960 (+5 yr, the source says “circa”)“ca. 1960: - (sweep second)”
Identity
A caliber is three separate things and this reference keeps them apart: the construction, the names it is sold under, and the article a brand actually bought. A watch model points at an execution — never at a bare construction — which is why “same caliber” is almost never a complete answer.
IDesign — the construction
Bifora 91
movementproducer: Biforaarchive filing
IIDesignations — 0 names
No designation is recorded for this design yet.
IIIExecutions — 1 article
No source in this corpus states which grade any Bifora 91 was bought at. That unknown is stored as a real row rather than left blank, so it can be counted, filtered and excluded from any comparison that would otherwise assume parity.
Specifications
| Property | Value | Scope | Status | Sources |
|---|---|---|---|---|
Jewels build.jewel_count | 17 | — | staged | |
Seconds display disp.seconds_display | small | — | staged | |
Seconds display disp.seconds_display | central | optional execution | staged | |
Movement diameter geom.diameter_mm | 21.3 mm | — | staged | |
Movement height geom.height_mm | 3.9 mm | — | staged | |
Frequency osc.frequency_vph | 18000 vph | — | staged | |
Shock protection osc.shock_protection | other | — | staged | |
Power reserve (typical) power.reserve_typical_h | 31 h | — | staged | |
Winding mode wind.mode | manual | — | staged |
Where a property carries more than one value, the values have different scopes — an official spec sheet and observed hardware, say. Different scopes are not a disagreement, so both are accepted and both are shown with the scope they apply to.
Lineage
The same relationships as the tree at the top of this page, with their sources. An absence in a column means no source stated one.
Ancestors · 0
Where this construction came from. Read up the arrows.
None recorded. An absence here means no source stated one, not that none exists.
Descendants · 1
What came from it — revisions, variants, clones, licensed copies.
- Dugena 712 (Bifora 91)ébauche of
Related · 0
Stored in a different table from descent. A successor is not a child.
None recorded. An absence here means no source stated one, not that none exists.
Sources
- 1Internet Archivehttps://web.archive.org/web/20051220100516/http://www.ranfft.de:80/cgi-bin/bidfun-db.cgi?10&&0&uswk&Bifora_91&archivetier 2retrieved 2005-12-2011 facts on this page
- 2Internet Archivehttps://web.archive.org/web/20230907054410/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&Dugena_712&archivetier 2retrieved 2023-09-071 fact on this page