Testing & Calibration

Dry runs (Section 4.1)

Leak-check the assembled system with argon, targeting <50 sccm leakage at 50 mbar over ambient.
Heat-soak the hot zone to 1000 °C using an empty liner. Verify element balance, pyrometer agreement, and thermal uniformity before pushing to full process temperature.
Pump down the refining pot, engage the cold-trap with water/ice, and confirm condensation control and vacuum stability.
Exercise interlocks, emergency stops, and data logging while the system is at temperature to ensure safe recovery paths.

Sieve feedstock to ≤250 µm and bake at 150–200 °C to remove moisture and surface salts.
Perform a LIBS scan (190–900 nm) across representative samples to estimate oxide fractions (Fe-oxides, SiO₂, Al₂O₃, CaO, TiO₂, alkalis). Save the spectra with the batch record.
Compare measured composition to recipe limits. Adjust staging times or potentials if impurities run high.

Validate pyrometers against a calibrated reference or high-temperature blackbody during the dry run.
Zero and span vacuum gauges (Pirani and capacitance manometer) using known pressure references.
Run the RGA under clean vacuum to establish baseline spectra before processing.

Proceed to Operation Manual only after all dry-run criteria are met, feed characterization data is logged, and calibration records are stored.