How to interpret gas flow conversion results
Sanity checks after converting sccm to kg/hr or g/min—what to compare and common misreads.
By Semiconductor Tools Editorial Team · Last updated: 2026-06-14
Unit conversion is mechanical; interpretation is where errors affect recipes, abatement sizing, and cost models. After any conversion, ask: does the mass flow make physical sense for this gas, this MFC range, and this process step?
Sanity check workflow
- Confirm STP assumption matches MFC calibration (0°C, 101.325 kPa on this site).
- Verify gas species selected matches physical gas and K-factor in hardware.
- Compare kg/hr with bulk gas invoice or cylinder usage over known time.
- For dilute reactants, cross-check partial pressure via Gas Mixture Calculator.
- Convert process load to throughput via Throughput Converter for vacuum balance.
Worked example — 500 sccm N₂ purge for 30 min
- MFC Converter: 500 sccm N₂ → 0.0375 kg/hr.
- 30 min run → 0.0375 × 0.5 = 0.0188 kg N₂ consumed.
- If cylinder log shows 0.5 kg used for the same step, investigate duplicate MFC paths, leak, or wrong gas selection in converter.