Characterizing the temporal light modulation of the LED products replacing linear fluorescent lamps

The transition from linear fluorescent lamps to LED products has reintroduced problematic temporal light modulation (TLM, also known as flicker) in commercial and educational spaces. This study measured the TLM performance of 58 LED products, beginning with tubular light-emitting diodes (TLEDs) and then expanding to other lighting products that are commonly selected when switching from linear fluorescent to LED. Nearly 25% of the products measured exceeded the TLM thresholds recommended by ANSI/IES TM-39-25, indicating poor TLM performance, although performance varied across product categories. Type B TLED lamps had the poorest TLM performance, with nearly half failing to meet the minimum TLM threshold. As many products are marketed as having low to no flicker, it may be difficult for building owners and operators to differentiate among LED products.