How is the nighttime lighting performance of high-mast lights evaluated?
Evaluating the nighttime lighting performance of high-mast lights requires on-site measurements based on the following indicators:
1. Horizontal Illuminance: Arrange measurement points in a grid pattern (e.g., 10m × 10m) on the target ground area. Use an illuminance meter to measure values and calculate the average, minimum, and maximum illuminance, as well as the uniformity ratio U2 (minimum/average).
2. Vertical Illuminance: For locations requiring the identification of vertical objects (such as container serial numbers), vertical illuminance must also be measured (at a height of 1.5 meters above the ground).
3. Glare: Use a luminance meter to measure the luminance of the luminaires within the field of view and calculate the Glare Rating (GR). Alternatively, employ a subjective evaluation method: observe the lighting from various angles and record whether it causes glare or visual discomfort.
4. Color Temperature and Color Rendering: Use a spectrometer to measure color temperature and Color Rendering Index (CRI) to verify compliance with design specifications.
5. Flicker: Use a mobile phone or high-speed camera to record the light and observe whether visible flickering occurs.
6. Shadows: Observe whether there are significant shadowed areas, particularly in the zones where light beams from multiple luminaires overlap.
7. Light Pollution: Measure vertical illuminance or illuminance levels at nearby sensitive locations (such as residential windows) and compare the results against local light pollution standards. Evaluations should be conducted after the luminaires have stabilized (typically 30 minutes after switching on LEDs). If measured values deviate from design values by more than ±20%, the luminaire angles or power output should be adjusted. Finally, a lighting inspection report should be issued to serve as the basis for acceptance.
