Simple radon level chart card with background

Who it’s for

Building managers, property owners, and occupational health officers ask “how has radon trended here recently?” The simple chart with background combines compact trend visualization with a full-card color signal readable from a distance.

What it does

A sensor reporting radon = 45 Bq/m³ renders a time-series trend chart on a card whose background color reflects the current severity: green for Safe (0–100 Bq/m³), orange for Elevated (100–200 Bq/m³), and red for High (above 200 Bq/m³).

• Full-card background color communicates current risk at a glance from a distance
• Trend chart of radon concentration over the selected dashboard time window
• Shows one sensor’s data per widget; add multiple widgets to compare trends and current status across zones

How to set up

Data keys

Key	Role	Type	Description
radon	Chart series	Timeseries	Radon concentration in Bq/m³; change the key name to match your device’s telemetry key
Latest	Latest value	Timeseries	The headline figure above the chart. Its own color ranges are where the band colors are edited

The widget ships with a simulated function datasource key labeled Radon level, so it draws random values until you point the datasource at a device and rename the key.

To point it at your own device: open the dashboard in edit mode, open the widget’s Datasources, pick the entity or entity alias, and replace the function key with the key your device reports.

Value ranges

Range (Bq/m³)	Level	Color
0–100	Safe	Green
100–200	Elevated	Orange
200+	High	Red

How to customize

• To change the time window — adjust the dashboard time filter to show the last hour, day, or week of radon readings.
• To change the severity thresholds — edit the color ranges on the Latest data key to match your national regulatory reference levels.
• To change the background colors — edit the color of each range on the Latest data key.

Tips

• On a wall display, the colored background signals the current radon risk from across the room while the embedded chart shows whether the overnight accumulation is still building or already clearing with ventilation.
• Use consistent severity colors across all indoor air quality widgets so building staff can interpret a red card anywhere on the dashboard without reading the label.
• For compliance reporting, export the time-series data covering the inspection period; the colored chart makes the risk bands immediately legible to inspectors reviewing the printout.