1. What is Illuminance?

Definition: Illuminance measures the amount of luminous flux falling on a surface per unit area.

Purpose: It helps lighting designers and engineers determine appropriate lighting levels for spaces.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( E \) — Illuminance (lux)
• \( \Phi \) — Luminous flux (lumens)
• \( A \) — Area (square meters)

Explanation: The total luminous flux is divided by the area it illuminates to determine the illuminance level.

3. Importance of Illuminance Calculation

Details: Proper illuminance ensures adequate lighting for tasks, energy efficiency, and compliance with lighting standards.

4. Using the Calculator

Tips: Enter the luminous flux in lumens and the area in square meters. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical illuminance level for offices?
A: Most offices require 300-500 lux for general work areas.

Q2: How does illuminance differ from luminance?
A: Illuminance measures light falling on a surface (lux), while luminance measures light emitted or reflected from a surface (cd/m²).

Q3: What's the illuminance in direct sunlight?
A: Direct sunlight can provide about 100,000 lux, while overcast daylight provides about 1,000 lux.

Q4: How do I find the luminous flux of a light source?
A: Check the product specifications - it's typically listed in lumens on the packaging.

Q5: What's the relationship between lux and foot-candles?
A: 1 lux = 0.0929 foot-candles, and 1 foot-candle = 10.764 lux.