… Hydrometers and similar floating instruments, thermometers, pyrometers, barometers, … recording or not, and any combination of these instruments. …
Explanatory notes
… 90.25 ‑ Hydrometers and similar floating instruments, thermometers, pyrometers, barometers, … (e.g., Baumé, Brix, Balling, Bates, Gay‑Lussac, Richter, Tralle, Sikes, Stoppani, etc.). Nicholson’s hydrometer is … deformation of the capsules or of the tube is amplified and transmitted to a pointer indicating the atmospheric pressure …