F&G Coverage Studio · Mehul Wadhwa

FIRE & GAS MAPPINGEXAMPLE DATA

1ooN Coverage

—

Detected by ≥ 1 detector

2ooN Coverage

—

Detected by ≥ 2 detectors

Target

≥ 85%

Selected zone criterion

Status

Calculating

Fire zone	Deck / assessment EL	Gas coverage	Flame coverage	Grid step

Each polygon is assessed independently. Overlapping polygons are not summed into a combined area.

Detector properties

Select a marker, or place a detector.

Place a new detector

Detector type

New tag (optional)

Cloud radius (m)Coverage shape

Its deck EL (m)

Detector deck construction

Place by coordinates

Enter actual X / Y / Z. One detector is shared across all calibrated views.

Easting / X Northing / Y

Elevation / Z (m)

DETECTOR TAGS 6

Drawing & scale

Calibrated

Upload plan drawing / model plan viewPDF, PNG, JPG or WebP · up to 40 MB

Example plot plan

20 drawing pixels = 1 metre

Plot-plan coordinates

Calibrate the drawing, then click a known grid intersection and enter its actual Easting and Northing.

No point selected.

Base Easting / XBase Northing / Y

Coordinate unitCoordinate north (°)

Base elevation / Z (m)

270° = drawing up · 0° = right · 90° = down. Use grid/plant north for the coordinate axes.

No coordinate reference set.

Changing the reference or scale keeps markers in place and recalculates their coordinates. Elevations and coverage ranges remain in metres.

Model image views

Upload the model’s plan view as the coverage drawing above. Add upright parallel/orthographic images looking North, South, East and West here. All views share the same detectors.

Image view

Choose a view in the drawing toolbar, then calibrate its image and base point below.

No base point selected.

Base EastingBase Northing

Base elevation (m)E/N unit

Use one common project datum. The plan view calculates zone coverage. Cardinal views project detector positions and elevations; they show gas-cloud geometry without calculating another coverage percentage. An angled reference image is for visual context.

For side-image clicks, enter Northing / Y in Properties for North/South views, or Easting / X for East/West views. Full X/Y/Z entry works in every calibrated cardinal view.

PHAST gas cloud

Enter the ellipsoid’s half dimensions from PHAST to calculate an equivalent sphere diameter.

Half-length rₗHalf-width r𝓌

Half-height rₕDimension unit

Equivalent sphere diameter—

D = 2 × ∛(rₗ × r𝓌 × rₕ)

Cloud radius · D ÷ 2: —
Ellipsoid volume: —

Enter the three half dimensions from the same PHAST cloud contour.

Alarm setpoint (% LFL)

Process stream / case

Release / weather notes

Use all three semi-axes from the same concentration contour and release/weather case. The alarm setpoint labels the result; it does not alter the entered cloud dimensions.

Unsaved calculation

Saved cloud cases

Save project keeps these cases with your drawing. The sphere preserves ellipsoid volume; it does not reproduce the plume shape or run PHAST dispersion modelling.

Review criteria

Calculate coverage for

Zone 2ooN target (%)Grid step (m)

Use elevation geometry

Plan view: elevations are recorded; coverage stays on the same deck.

Gas 2ooN uses gas detectors only. Flame overlap uses flame detectors only. Each zone has separate targets.

How to use this workspace

Upload a drawing and calibrate a known dimension.
In Drawing, pick a known grid reference, enter its Easting/Northing and set north. Place detectors with the coordinate fields in Properties.
Draw each fire-zone polygon, give it a name, and set its deck elevation and construction.
Choose a detector type and enter its range. Flame detectors also need a full cone angle and heading.
Review every zone in the coverage table. Click a result to inspect its heatmap.
Save a project file to continue later.

Directional heading: 0° points right; 90° points down. Escape cancels a tool. Delete removes the selected detector. Ctrl/⌘ + Z undoes an edit.

Elevation geometry uses a spherical gas-cloud radius in all directions. Cross-deck coverage is permitted only between open-grating decks. Solid-deck zones remain isolated from other deck levels. All elevations must use the same datum. Flame elevation uses an idealised horizontal/vertical angular field of view and tilt.

About geometric gas-cloud mapping

Ready for the next discussion.