Tri-clamp bubbler gravity caps: measure specific gravity from the lid with two dip tubes — dimension sheet Source: Xem Studio, https://xemstudio.com/objects/tri-clamp-bubbler-gravity-caps/ (CC BY 4.0) Basis: Xem Studio design: the standard 1½ in solid cap with two Ø4.76 × Ø2.4 tubes whose open ends are a fixed Δh apart, each with a 4 mm hose barb; the method is hydrostatics, Δp = ρ g Δh Catalog version: 2026-10-20 Sizes: see table below - Push a slow trickle of gas (the same gas as the headspace, CO₂) down both tubes; each tube's back-pressure equals the liquid head above its tip. The difference between the two is ρ g Δh, so specific gravity = Δp / (997 × 9.81 × Δh). The fill level and the headspace pressure cancel out, as long as both tips stay under the liquid. - Read the difference with one differential pressure sensor across the two barbs. With Δh 200 mm, water gives 1956 Pa and every 0.001 of gravity adds about 2 Pa, so pick a sensor that resolves 1 Pa or better; a longer Δh gives more signal. - Nothing goes in the vessel but two thin tubes: no floating hydrometer, no radio through stainless steel. - Every clamp face is the ISO 2852 profile used across this site: 2.85 mm rim, flat face with the gasket groove (K 1.6 deep, R3 1.2 bottom, 23° walls, P2 0.8 edges) on C2, 20° back cone. Flange C3 / groove C2 / tube OD × wall, mm: ½–¾ in 25.0 / 20.4 (derived) / 12.7–19.05 × 1.65; 1–1½ in 50.5 / 43.5 / 25.4–38.1 × 1.65; 2 in 64.0 / 56.5 / 50.8 × 1.65; 2½ in 77.5 / 70.5 / 63.5 × 1.65; 3 in 91.0 / 83.5 / 76.2 × 1.65; 4 in 119.0 / 110.0 / 101.6 × 2.11; 6 in 166.9 (6.570 in) / 156.5 / 152.4 × 2.77; 8 in 217.7 (8.570 in) / 207.0 / 203.2 × 2.77; 10 in 268.5 / 261.0 / 254.0 × 3.40; 12 in 319.3 / 311.8 / 304.8 × 3.40. deep_tube_in dh_mm dp_water_pa dp_sg_1050_pa pa_per_0.001_sg 12 100 978 1027 1 12 150 1467 1540 1 12 200 1956 2054 2 16 100 978 1027 1 16 150 1467 1540 1 16 200 1956 2054 2 Files elsewhere (not hosted by Xem Studio; license as stated by the publisher): - physics: Hydrostatic pressure: Δp = ρ g Δh (two bubbler tubes at a height difference Δh give the density of the liquid between them) — web — physics — https://en.wikipedia.org/wiki/Hydrostatics - GW Kent: Tri-clamp fittings guide: tube OD, flange OD and ID per size to 12 in; solid cap thickness — web — publisher's guide; dimensions cited — https://www.gwkent.com/triclamp-guide - Rubber Fab: Tri-Clamp gasket dimensional chart: gasket ID, OD and bead diameter per size (2 in bead 2.22 in / 56.50 mm, 1.5 in 1.71 / 43.50, 3 in 3.29 / 83.50) — PDF — maker chart; dimensions are facts [verify license at link] — https://shop.andersonprocess.com/media/assets/product/documents/rubber-fab-tri-clamp-dimensions.pdf Free files (CC BY 4.0, Xem Studio; STEP + STL, 6 parts): https://xemstudio.com/files/hardware/tri-clamp-bubbler-gravity-caps/index.json API: https://xemstudio.com/api/geometry?object=tri-clamp-bubbler-gravity-caps