Isotech 17402B Gallium Apparatus
- Simple, automatic and safe operation
- Reproducibility day-to-day of ±0.000025°C
- 20 years of world-wide deliveries without breakage
- 99.999999% purity
The Isotech 17402B Gallium Apparatus is a purpose‑built system designed exclusively for the realisation and long‑term maintenance of the Gallium melting point (29.7646 °C), one of the primary reference points on the International Temperature Scale of 1990 (ITS‑90). Unlike general‑purpose equipment adapted for fixed‑point work, the 17402B is engineered from the ground up to deliver a stable, safe and reproducible gallium plateau, day after day. It has been used for more than twenty years in national metrology institutes and primary laboratories worldwide.
Engineered for automatic, reliable plateau realisation
The apparatus is optimised to melt the gallium cell coaxially over 12 to 16 hours, producing an exceptionally stable plateau. A unique feature is its ability to freeze the cell from the bottom upward, preventing mechanical stress caused by the expansion of gallium during solidification. This protects the cell and ensures long‑term reliability. The system operates fully automatically. A precision electronic controller maintains the plateau, and the apparatus can be started by a timer so that the plateau is ready at the beginning of the working day. After use, the system can be recycled overnight.
Simple, safe and completely self‑contained
The 17402B requires no external connections other than mains power. All thermal control, safety features and regulation are built in. A thermal sink ensures that the gallium always freezes in the correct orientation, eliminating the risk of cell rupture.
Proven performance in primary laboratories
The Gallium Apparatus and the associated Isothermal Gallium Cell (Model 17401) have a long and successful history in primary and national laboratories. Their stability and reproducibility are key reasons why the gallium point is widely used as a reference in precision thermometry. Each unit is manufactured to BS 5750 and ISO 9000, and undergoes extended testing in the Isotech UKAS laboratory. Only after meeting all performance criteria is the apparatus released.
Performance and specifications
The 17402B offers:
- > Uncertainty: 0.25 mK (with cell)
- > Plateau duration: minimum 12 hours, typically 16 hours
- > Cycle time:
- from 20 °C to plateau: max. 1 hour
- full cycle including controlled freezing: 3–4 hours
- > Temperature: fixed at 29.7646 °C
- > Power: 75 W typical
- > Supply: 100–130 V or 208–240 V, field‑changeable
- > Dimensions: 429 × 259 × 181 mm
- > Weight: 8.4 kg
Gallium Cell (Model 17401)
The gallium cell (model 17401) may be used independently in a well‑controlled bath, but the advantages of the 17402B — automatic operation, plateau stability and cell protection — make it the preferred choice for most laboratories.
The Isotech 17402B Gallium Apparatus is a fully optimised, safe and exceptionally stable system for realising the gallium melting point. With automatic plateau generation, controlled freezing, proven reliability and an uncertainty of just 0.25 mK, it is an essential standard for laboratories requiring the highest precision in ITS‑90 thermometry.
