By the mid-1970s, Lukyanov hydraulic integrators were in use at 115 organizations across 40 Soviet cities, displaced by digital computers in the early 1980s

A 2000 magazine account by O. Solovyova, writing in Наука и жизнь (Science and Life; the page credits the article as condensed from a Polytechnic Museum collection but states no affiliation for the author), gives a specific scale figure for the deployment of Vladimir Lukyanov's hydraulic integrator that no source previously in the vault carried: by the mid-1970s, integrators of the "IGL" line were in operational use at 115 production, scientific, and educational organizations spread across 40 cities of the USSR. The account also narrows the device's displacement point: it was specifically the arrival of compact, cheap, high-speed digital computers in the early 1980s — not simply "the 1980s" in general — that fully superseded the hydraulic integrator's capabilities.

This is [unverified-quant — needs a second independent primary]: the 115/40 figure and the early-1980s displacement point rest on this one Tier 2 source alone. No second, independent account carrying these exact numbers was located this session. See question-corroborate-lukyanov-service-scale-figure. The broader claim that the device remained in use "into the 1980s" is separately corroborated by two Wikipedia articles (Tier 4) already cited on the parent claim-note, so only the specific counts — not the general timeframe — are in question here.

2026-08-20 update: a dedicated corroboration search (a follow-up capture routed by the question above) found six pages carrying this figure and traced every one of them back to this same Solovyova sentence — no independent count was found anywhere. The flag above stands and should be read as strengthened, not resolved. See claim-lukyanov-115-figure-no-independent-source-located, claim-wikipedia-water-integrator-citation-resolves-to-same-nkj-ru-source, and claim-lukyanov-integrator-1990s-claim-is-transmission-drift for the full search.