Excel workbook for engineers

One gas composition. Three standards. Every answer in seconds.

Calorific value, compressibility, density and orifice flow, calculated to ISO 6976, AGA Report 8 and ISO 5167. Locked, no macros, with checks that catch bad inputs before they reach your report.

  • ISO 6976
  • AGA-8 DETAIL
  • ISO 5167-2
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Results sheet showing gas properties, AGA-8 results and orifice flow with uncertainties

Stop juggling three spreadsheets for one gas stream

Choose what you need, fill the yellow cells, read the Results sheet. Use any one calculation or all three together.

A

ISO 6976 gas properties

  • Gross and net calorific value
  • Molar, mass and volume basis
  • Wobbe index, real-gas density, relative density
  • Uncertainty for each result
B

AGA-8 DETAIL

  • Compressibility factor and density
  • Speed of sound
  • Cp, Cv and isentropic exponent
  • At your flowing pressure and temperature
C

Orifice flow, ISO 5167-2

  • Mass, volume and energy flow
  • Discharge coefficient, expansion factor, Reynolds number
  • Pressure loss and flow uncertainty
  • Limits-of-use checks

Three steps. Nothing to configure.

The workbook has three visible sheets: Instructions, Inputs and Results.

  1. Pick your calculationsAnswer Yes or No for A, B and C. Unused blocks grey out.
  2. Enter the gas21 components, as mole fraction or mole percent, with optional normalisation.
  3. Read the resultsValues, units, uncertainties and warnings appear on the Results sheet.

See it working

Select an image to enlarge. The example data is invented.

Results: properties, flow and uncertainty on one page.
Inputs: yellow cells only, with a live status line.

Watch it work

A two-minute walkthrough: enter a gas, choose your calculations, read the results, and see how mistakes are caught.

Built to be hard to misuse

  • Every input is checked, and a red message appears next to the problem field
  • Results stay blank until the inputs are valid, so you never read a half-answer
  • Warnings when the orifice is outside ISO 5167-2 limits of use
  • Calculation sheets are hidden and the workbook is protected against stray edits
  • No macros, so there is nothing to enable and nothing to install
  • Pressure basis is explicit: absolute kPa, so no gauge or absolute mix-ups

Checked against reference calculations

The workbook was compared with independent reference results before release.

6test gases compared with GERG-2008, from lean to sour, 0.2 to 12 MPa
≤ 0.11 %difference in compressibility factor and density across those cases
Exactmatch with an ISO 6976 reference calculation for the same composition

AGA-8 is quoted by its own standard at about 0.1 % uncertainty in its normal range. Heat capacities differ more between AGA-8 and GERG-2008 (about 1 % in the cases tested). Results are for engineering use and should be checked for design, custody-transfer or safety decisions.

Questions

What do I need to run it?

Microsoft Excel on a desktop is recommended. The file has no macros. You should also hold your own copies of ISO 6976, ISO 5167 and AGA Report No. 8, because their text is not included.

Can I change the formulas?

No. The calculation sheets are hidden and protected so results stay consistent. You edit only the yellow input cells.

Which components can I enter?

Twenty-one: methane through n-decane, nitrogen, CO2, hydrogen, oxygen, CO, water, H2S, helium and argon. Amounts can be mole fractions or mole percent.

Does it work for any pipe size?

The orifice calculation follows ISO 5167-2 and warns you when your pipe, beta ratio or Reynolds number is outside its limits of use.

What if something is wrong with my inputs?

A red message tells you which field to fix, and results stay blank until it is corrected.

Get your gas calculations done once, correctly

One Excel file, three standards, instant download.

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