CF 24B

Overview

CF 24B is a CF (cupellation furnace) developed for the standard fire assay (cupellation) to check the purity of precious metals. Maximum temperature: 1200°C. The furnace is designed for the lead cupellation melting procedure in accordance with the International Hallmark Convention reference method and UK Assay Office ISO11426:1999. Valve‑regulated airflow is preheated before entry to the furnace chamber. Silicon carbide heating elements are built into the furnace base and roof to provide even heating of the cupel, resist thermal shock, and offer long life at high temperatures. The silicon carbide furnace base and roof protect the heating elements and resist the corrosive fumes produced during the cupellation process. Fume gases exit via an insulated extraction flue fitted with a condensable lead collector and a removable emptying container. The furnace has a vertically opening, upward‑lifting balanced door with an observation window, an overtemperature safety cut‑out, and a 7 day / 24 hour timer. Used to perform cupellation (fire assay) procedures to check the purity of precious metals under the requirements of the “Precious Metals Convention”, “Hallmarking Convention” or “Vienna Convention”. The unit is specifically configured for the lead cupellation melting procedure per UK Assay Office ISO11426:1999. The cupellation assay generates hazardous fumes; when a suitably designed furnace and fume extraction system are applied, the fumes are routed out through the insulated extraction flue and collected in the condensable lead collector so they do not endanger the user or the furnace insulation.