How to Read Red Light Panel Specs: Watts, LEDs and Irradiance
Wattage tells you how much electricity a panel draws. Irradiance tells you how much light lands on a surface. They are not the same number, and a listing that quotes only one of them leaves out half of the picture.
Wavelength
Check which bands the LEDs give off. MARS 400 lists 660 nm (red) and 850 nm (near-infrared), with 30 LEDs of each. A panel that names no wavelengths, or only a range, is harder to compare.
LED count
More LEDs can mean more coverage, but the count alone says little: LEDs differ in output and are driven at different levels. Look at the count together with the power and the irradiance. MARS 400 has 60 LEDs in total.
Power in watts
Power is the electricity the panel draws from the wall: 82 W ±5% for MARS 400. Part of that becomes light and part becomes heat, which is why a panel can feel warm. A higher wattage tells you the panel draws more electricity, not that it delivers more light to you.
Irradiance in mW/cm²
Irradiance is the light power that reaches each square centimetre of a surface. It falls as you move away from the panel, so a figure means little without the distance it was measured at. MARS 400 lists at least 219 mW/cm² at the LED surface and at least 130 mW/cm² at 15 cm, according to the product specification.
Quick answers
Is a higher wattage always better?
No. Wattage is the electricity the panel draws. Compare the irradiance at the same distance and the wavelengths instead.
What does ±5% mean?
It is the tolerance on the stated power. A panel rated 82 W ±5% can draw from about 78 W to about 86 W.
Why is the figure at the LED surface higher than at 15 cm?
Light spreads out as it travels, so the same power covers a larger area further from the panel and each square centimetre receives less.
Questions to ask before you buy
- At what distance was the irradiance measured?
- Which wavelengths are included, and how many LEDs of each?
- Is the power the electrical draw, or a claim about light output?
- Is there a timer, and which modes does the panel have?
- What warranty comes with it, and who looks after it in Hong Kong?
- Does the user manual give the distance and session guidance?
MARS 400 at a glance
- LEDs: 60 in total, 30 at 660 nm (red) and 30 at 850 nm (near-infrared).
- Power: 82 W ±5%.
- Irradiance: at least 219 mW/cm² at the LED surface, at least 130 mW/cm² at 15 cm.
- Modes: Red, NIR or Combined, with auto-off after 10 minutes.
- Size and weight: 36 × 30 × 10 cm, 2.6 kg.
- Power supply: 100-240 V AC adapter, 24 V DC output.
Specifications describe the product, not the result. See the MARS 400 page for the full list.
