Edge-Lit LED Strip: Bare LED/Lens/Potting Compound Luminous Efficiency and Color Temperature Evaluation

Test Objectives

1) Document changes in luminous efficiency, color temperature, and CRI data across three distinct production stages of edge-lit LED strips: bare LED board → LED with lens → lens with potting compound. Provide data support for product development.

2) Evaluate the impact of varying power levels and strip lengths on brightness, color temperature, and other parameters for edge-lit LED strips.

Test Samples

Test Method

Record raw LED data: Sample light strips are tested using an integrating sphere and spectrophotometer to record corresponding brightness, luminous efficacy, color rendering index, color temperature, and other data.

Measurement Equipment and Environment

• Integrating sphere optical testing system / High-precision spectrophotometer
• Temperature: 28°C ±5°C
• Humidity: 65% ± 5%
• Test Voltage: DC 24V
• Test Date: 2024-04-15

LED Integrating Sphere Test Data

LED Chip Type for This Sample: SMD2835; Sample Supplier: MASTER OPTRONICS LED

Edge-lit LED Strip: Test Data for Light Output and Color Temperature of Bare Lamps/Lens/Potted Versions

Test Data Analysis

Below are the luminous efficacy, color temperature, and CRI data along with technical analysis for side-lit LED strips across three production stages: bare LED chip boards, LEDs with lenses, and lenses with potting compound:

1. Luminous Efficacy Variation

• Bare PCB → Lens: Four data sets were sampled: Set 1 showed a 3.3% efficacy drop, Set 2 a 1.1% drop, Set 3 a 3.3% drop, and Set 4 a 1.9% drop. The average efficacy reduction was approximately 2.4%.

• Lens → Potting: We extracted data from four groups: Group 1 showed a luminous efficacy decrease of approximately 0.34%, Group 2 decreased by 1.8%, Group 3 decreased by approximately 2.1%, and Group 4 decreased by approximately 4.5%. Taking the average, the luminous efficacy decrease was approximately 2.2%.

2. Color Temperature Changes

• Bare PCB → Lens: As shown in the charts above, the color temperature remains essentially unchanged when adding a lens to the bare PCB. This variation is negligible.

• Lens → Potting: Color temperature variation is also minimal. Groups 1, 3, and 4 show shifts of only about 80K. The largest change occurs in Group 2, where color temperature drops from 6435K to 6273K after encapsulation, a difference of 162K.

3. Color Rendering Index (CRI) Changes

• Bare PCB → Adding Lens: CRI remains unchanged.
• Adding Lens → Potting: Only a minor change of 0.1 to 0.2.

Summary

Test results are summarized in the table below: Effects of lensing and potting processes on luminous efficacy, color temperature, and CRI of side-lit light strips: Lensing reduces luminous efficacy by approximately 2.4%, with no change in color temperature or CRI. Potting with silicone reduces luminous efficacy by about 2.2%, lowers color temperature by 70-165K, and decreases CRI by 0.1-0.2.