Simple carbon monoxide (CO) chart card

Who it’s for

Environmental health officers, air quality managers, and smart city operators ask “how has CO concentration at this station trended over the last few hours or days?” They want a compact trend chart that fits into a multi-station overview without the overhead of a full chart card.

What it does

A monitoring station streams carbon telemetry and the widget renders a time-series chart of those readings, color-coded by severity: green for Good (0–5 mg/m³), light green for Moderate (5–10 mg/m³), orange for Elevated (10–25 mg/m³), dark orange for High (25–50 mg/m³), and red for Hazardous (above 50 mg/m³). The chart fills the card without a large numerical readout, maximizing the visible time window.

• Trend chart of CO concentration over the selected dashboard time window
• Color-coded by severity at each point in time across five bands
• Shows one sensor’s data per widget; add multiple widgets to compare trends across stations

How to set up

Data keys

Key	Role	Type	Description
carbon	Chart series	Timeseries	Carbon monoxide concentration in mg/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 Carbon monoxide, 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	Level	Color
0–5	Good	Green
5–10	Moderate	Light Green
10–25	Elevated	Orange
25–50	High	Dark Orange
50+	Hazardous	Red

How to customize

• To change the time window — adjust the dashboard time filter to show the last hour, day, or week of CO readings.
• To change the severity thresholds — edit the color ranges on the Latest data key.
• To change the chart colors — edit the color of each range on the Latest data key.

Tips

• Use this chart in a grid alongside simple chart cards for NO₂, O₃, and SO₂ to give operators a side-by-side multi-pollutant trend view without cluttering the dashboard with large value cards.
• Set the time window to 24 hours to capture the typical daily CO cycle driven by morning and evening traffic peaks, making anomalies easy to spot.
• A sustained upward trend over several days rather than a spike-and-return pattern usually indicates gradual equipment degradation or a new nearby emission source.