Indoor illuminance card

Who it’s for

Facility managers, building automation engineers, and workplace managers ask “is the light level in this space adequate for the tasks being performed right now?” They monitor illuminance to ensure task areas meet occupational lighting standards and to validate that automated lighting controls are responding correctly to occupancy and daylight.

What it does

A sensor reporting illuminance = 350 lx displays the reading on a color-coded card: dark gray for Dim (0–100 lx), orange for Low (100–300 lx), dark orange for Moderate (300–500 lx), and red for Bright (above 500 lx).

• Live illuminance reading in lx with automatic color coding across four bands
• Bands span the range from insufficient for safe navigation to potential glare risk from direct sunlight
• Shows one sensor’s reading per widget; add multiple widgets to monitor different task areas or zones

How to set up

Data keys

Key	Role	Type	Description
illuminance	Main value	Timeseries	Illuminance in lx; change the key name to match your device’s telemetry key

The widget ships with a simulated function datasource key labeled Illuminance, 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 (lx)	Level	Color
0–100	Dim	Dark Gray
100–300	Low	Orange
300–500	Moderate	Dark Orange
500+	Bright	Red

How to customize

• To change the band thresholds — open the widget settings and adjust the boundaries to match the lighting standard for your space (e.g., EN 12464-1 recommends 500 lx for office work).
• To change the band colors — edit the color for each level in the widget settings.
• To rename the units label — change the Units field in the widget settings if needed.

Tips

• Office task areas (desks, reading zones) typically require 300–500 lx; a Dim reading during working hours indicates a lamp failure, daylight harvesting over-correction, or an occupancy sensor that has prematurely dimmed the lights.
• Illuminance above 500 lx near windows on a sunny afternoon indicates direct sunlight penetration that may cause glare complaints; pairing this card with a blind-control widget lets operators correlate the illuminance spike with the blind position.
• For post-occupancy evaluation (POE) of a new lighting system, collect a week of hourly illuminance readings from key task areas to verify that the design intent — adequate light during occupied hours, dimming during unoccupied hours — is being met.