1. What is Illuminance?

Illuminance is defined as the number of lumens falling on a surface per unit area. It measures how much luminous flux is spread over a given area and is typically measured in lux (lumens per square meter).

2. How Does the Calculator Work?

The calculator uses the illuminance formula:

Where:

• \( E \) — Illuminance (Lux)
• \( \Phi_m \) — Magnetic Flux (Weber)
• \( A \) — Surface Area (m²)

Explanation: This formula calculates the illuminance by dividing the total magnetic flux by the surface area over which it is distributed.

3. Importance of Illuminance Calculation

Details: Accurate illuminance calculation is crucial for lighting design, architectural planning, photography, and various scientific applications where proper light distribution is essential.

4. Using the Calculator

Tips: Enter magnetic flux in Weber and surface area in square meters. All values must be valid (positive numbers greater than zero).

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between illuminance and luminance?
A: Illuminance measures the amount of light falling on a surface (incident light), while luminance measures the amount of light reflected or emitted by a surface.

Q2: What are typical illuminance values for different environments?
A: Office lighting: 300-500 lux, outdoor daylight: 10,000-25,000 lux, moonlight: about 1 lux.

Q3: How does surface area affect illuminance?
A: For a constant magnetic flux, increasing the surface area decreases the illuminance, as the same amount of light is spread over a larger area.

Q4: What units are used for illuminance measurement?
A: The SI unit is lux (lumens per square meter), though foot-candles (lumens per square foot) are also used in some regions.

Q5: Can this calculator be used for practical lighting design?
A: Yes, this calculator provides the fundamental illuminance calculation that forms the basis for more complex lighting design calculations.