Lighting Level and Uniformity Tests
Lighting level and uniformity tests ensure that a workspace meets safety, productivity, and compliance standards. These tests are crucial in cleanrooms, hospitals, laboratories, manufacturing plants, and commercial spaces, where proper lighting impacts visual accuracy, efficiency, and worker comfort.

1. Purpose of Lighting Level & Uniformity Testing
Ensures compliance with ISO, OSHA, EN 12464-1, ASHRAE, and IES standards.
Improves visibility in precision tasks (e.g., cleanroom work, medical procedures).
Prevents eye strain & fatigue, enhancing worker productivity.
Verifies even distribution of light across work areas.

2. Key Lighting Parameters
Illuminance (Lux or Foot-candles) → Measures light intensity on surfaces.
Uniformity Ratio (U₀ = E_min / E_avg) → Measures evenness of light distribution.
Glare Index (UGR – Unified Glare Rating) → Determines glare discomfort.
Color Temperature (Kelvin, K) → Defines light warmth or coolness.
Color Rendering Index (CRI, Ra) → Measures how accurately colors appear.

3. Recommended Lighting Levels
Application
Recommended Illuminance (Lux)
Uniformity Ratio (U₀)
Cleanrooms (ISO 5-8)
300 – 750
≥ 0.7
Hospitals (ICUs, ORs)
500 – 1000
≥ 0.7
Pharmaceutical Manufacturing
500 – 750
≥ 0.6
Laboratories
500 – 1000
≥ 0.6
Offices & Workstations
300 – 500
≥ 0.5
Industrial Assembly Areas
500 – 1000
≥ 0.6
Warehouses & Storage
100 – 300
≥ 0.4

4. Lighting Level & Uniformity Test Procedure
a. Equipment Required
Lux Meter (Light Meter) → Measures illuminance (Lux).
Grid Layout Plan → Defines measurement points.
Tripod Stand (for consistent height measurement).
b. Test Steps
Set up a measurement grid based on room size & standards.
Measure illuminance at multiple points (e.g., corners, center, and workstations).
Calculate average (E_avg) and minimum (E_min) illuminance.
Compute uniformity ratio (U₀ = E_min / E_avg).
Compare results with recommended values.

5. Pass/Fail Criteria
Pass: Lighting levels & uniformity meet or exceed standards.
Fail: Lighting is too dim or uneven → requires adjustment or upgrades.

6. Corrective Actions for Non-Uniform Lighting
Adjust fixture placement for better light distribution.
Use diffusers to reduce glare and shadows.
Increase or upgrade light sources if illuminance is too low.
Ensure proper fixture maintenance (cleaning & replacing lamps).

7. Applications of Lighting Tests
Cleanrooms & Laboratories → Prevents contamination & enhances precision.
Hospitals & Medical Facilities → Ensures optimal visibility for patient care.
Manufacturing & Industrial Sites → Reduces errors & accidents.
Offices & Workspaces → Enhances comfort & productivity.
Would you like a detailed test protocol or help in interpreting results?