Native Excel functions — Type =ZS_ZFactor(...) in any cell. Works exactly like SUM or VLOOKUP. No menus, no dialogs, no context switching.
AGA-8 Detail Method — Full 21-component characterization. Methane through Argon, in the standard AGA-8 order. Not a simplified correlation — this is the real thing.
Built-in gas component list — Call =ZS_AGA8Gases() and a complete, properly ordered template spills into your worksheet. Fill in your mole fractions right next to it. No more guessing which component goes in which slot.
Spreadsheet-native workflow — Your compositions, conditions, and results all live in cells. Build sensitivity tables, link to upstream calculations, chart the results — all with standard Excel. The add-in stays out of your way.
Fast — Compiled native code, not interpreted VBA. Calculations complete in microseconds. Recalculate thousands of conditions without waiting.
Modern Excel support — Works with Excel 2007 through Microsoft 365. Dynamic array spilling for the gas list. Thread-safe functions that play nicely with Excel's multi-threaded recalculation engine.
Implements the AGA-8 Detail Characterization Method per AGA Report No. 8 (AGA8-DC92)
Native .xll add-in — compiled Delphi code, not VBA or COM automation
Supports both 32-bit and 64-bit versions of Excel
Thread-safe functions compatible with Excel's multi-threaded calculation
All 21 standard AGA-8 components supported
Mole fractions are automatically validated (must sum to 1.0 within tolerance)
Temperature and pressure inputs in °F and psia (consistent with common US practice)
Process engineers designing gas processing plants
Pipeline engineers calculating pressure drop and flow capacity
Reservoir engineers evaluating gas properties at varying conditions
Lab technicians validating gas composition analyses
Anyone who currently runs AGA-8 calculations outside Excel and pastes results back in