Support — N8 Orifice Meter Gas Calculation

N8 Orifice Meter Gas Calculation is a Windows desktop tool for AGA 3 orifice fiscal gas metering. This page covers common questions and how to get help.

1. Getting started

First launch

• Windows 10 build 17763 or later, x64.
• Internet connection required for first-time license activation.
• On first launch you will see a registration form — fill in your name, email, and (optional) company / phone. This starts a free 1-day trial bound to your machine.

Where the app installs

Standard install location: %LOCALAPPDATA%\N8 Orifice Meter Gas Calculation\. All calculation data, gas compositions, and meter setups are stored locally on your device.

2. Licensing

3. Frequently asked questions

My results differ from the flow computer report. Why?

Open the Summary tab and check the Report vs SQUARE deviation column. Small deviations (< 0.1 %) are usually rounding or reference-condition differences between the flow computer and AGA 3 / AGA 8 reference. Larger deviations indicate an input mismatch — most often gas composition, base pressure/temperature, or the discharge-coefficient equation the flow computer uses. The app shows the exact formula and substitutions used for each SQUARE number so you can trace any disagreement line by line.

The AI extraction filled a field with the wrong value

Every AI-populated field is marked with an amber verify chip. Click the chip to confirm or override the value. AI extraction never runs any calculation — the SQUARE numbers only come from the deterministic engine after you press Calculate.

Can I use it without an internet connection?

Yes, after first activation, for up to 72 hours between license checks. The AI extraction feature always requires internet because it sends the report to Google Gemini or Anthropic Claude (your choice, your API key).

The AI extraction is not working

• Check Settings → AI provider and confirm the API key is pasted.
• Google Gemini free tier has strict rate limits — if you see a 429 error, wait 60 seconds and retry, or switch to a paid Gemini tier / to Claude.
• The report file must be a PDF, PNG, JPG, or WebP. Scanned PDFs work; corrupted PDFs may fail.

How do I export the audit trail?

Use Export → XLSX for a spreadsheet with all inputs, formulas, substitutions, and iterations. Use Export → PDF for a printable report. Use Export → JSON snapshot to archive the full state (can be re-imported for review or audit).

My license was working, but now it says "Expired" — I have a paid license

Email us. The most common cause is that the license server could not reach your machine within the 72-hour grace window, and the app fell back to trial mode. We can re-issue the activation instantly after verification.

Can I install on more than one machine?

One license is bound to one machine. Contact us for a multi-seat quote if you need to deploy across a team.

4. Standards implemented

• AGA Report No. 3 (2012) — Orifice Metering of Natural Gas
• AGA Report No. 8 (2017) — Detail Characterization
• GPA 2172 (2009) — Calculation of Gross Heating Value
• GPA 2145 — Physical Constants
• NORCE-20-A101422-RA-1 (2020) — Handbook for Uncertainty Calculations for Gas Flow Metering Stations
• API 14.3.2 — Orifice geometry uncertainty defaults
• ISO 5167-2:2003 — Reader-Harris/Gallagher discharge coefficient

For discrepancies against these standards, please open a support ticket by email with: the campaign JSON snapshot, the standard clause you believe is misapplied, and the expected value with your derivation. We take standards conformance seriously and respond to every such report.

5. Privacy

See our Privacy Policy for full detail on what data is collected (license registration only), how AI extraction handles your reports, and your rights.

6. Bug reports & feature requests

Email na8awi@gmail.com with:

• App version (shown at the bottom of the About screen)
• Windows version
• A short description of the issue and the steps that trigger it
• If relevant: the JSON snapshot (Export → JSON snapshot) — this contains the full app state without any personal info