What Equipment Is Used?
A flicker meter or photometric sensor captures the light waveform at a high sampling rate. Test software then analyzes maximum output, minimum output, frequency, waveform shape, and modulation depth.
A phone camera may reveal dark bands, but it cannot provide dependable test data. Shutter speed, frame rate, and rolling-shutter behavior can make the same lamp look different between devices.
Which Metrics Matter?
Percent flicker describes the variation between maximum and minimum light output. Flicker index also considers waveform shape, helping distinguish products with similar modulation percentages but different pulse patterns.
Modern reports may include PstLM for short-term visible flicker and SVM for stroboscopic effects. These metrics are useful when comparing panel lights, downlights, and other commercial LED products.
Why Must Dimming Be Tested?
Flicker can increase when brightness is reduced. A fixture that performs well at full output may show stronger modulation at a low setting because the driver, dimmer, and control method interact differently.
Testing should cover full output, several intermediate levels, and the lowest stable setting. TRIAC, 0–10V, and PWM systems should be checked with the intended control equipment.
What Conditions Should Be Recorded?
Input voltage, mains frequency, ambient temperature, warm-up time, driver model, dimmer model, output level, and test distance should appear in the report. Samples must use the same electrical components planned for mass production.
| Measurement Item | What It Shows |
|---|---|
| Flicker frequency | How often output changes |
| Percent flicker | Modulation depth |
| Flicker index | Waveform severity |
| PstLM | Visible flicker response |
| SVM | Stroboscopic effect visibility |
How Should Results Be Reviewed?
One value cannot describe every temporal light effect. Buyers should request waveform graphs and results at several dimming levels, then compare samples using the final driver and control system. Consistent testing helps reduce flashing, camera banding, stroboscopic effects, and differences between approved samples and bulk production.