Example: You Buy A LED Lamp With The Label 600lm?
Since there is still missing a specification…..at which ambient or substrate temperature is this value?
Is it the luminous flux of the LED (from LED data sheet) or is it a measured value minus all losses (temperature, cover glass)?
The data sheet data of the manufacturers refer almost exclusively to 25°C substrate temperature.
In the quality test, the last process step, in the factory the values are measured. This measurement takes only fractions of seconds and no heating takes place yet.
Extract from the footnote of an LED data sheet:
1) Brightness values are determined with a current pulse duration of 25 ms.
In normal operation, LED lamps/LED lamps/LED tubes usually heat to 50°C or more, depending on the thermal design and ambient temperature. The temperature difference between the heat sink and the LED substrate lies between 7°C and 10°C.
The location of luminaires is mostly on the ceiling where the room temperature is highest.
In practice this usually means Tj>70°C and a lower brightness compared to the data sheet value by 15%.
If the indicated luminous flux is not a measured laboratory value, further losses (5-10%) may be applied by using optics or glass covers.
600 lm (LED data sheet) or in reality only 460 lm (customer use)?
LEDclusive.de presents the technical data transparently and completely.
15W 9006 Canbus LED Daytime Running Light 700LM 500Ma Car …
15W 800Lm H7 2835 15SMD 12V LED Car Fog Light White …
4Pcs 800Lm 3G15 P13W 2835 15SMD 15W Canbus Upgrade LED …
2 x 35W HID Xenon Replacement Headlight Light Bulb D1S/D1C …
2x Interior LED Spot Reading Light Switch Boat Motorhome …
5pcs/lot Mini led spotlight cabinet lamp high power AC85 …
Lamp 56 LED Solar Powered Flood Light Motion Sensor …
T10 5360 W5W 10SMD Error Free Car Super Bright Width Light …
2x 35W HID Xenon Replacement Headlight Light Lamp Bulbs …
T10 2.5W Xenon White Led Backup Reverse Lights Bulb 921 …
Wi-Fi Enabled Smart LED Light Bulb
2X Car 13 SMD 5050 LED Stop Tail Brake Turn Side Light …
Aliexpress.com : Buy G9 E14 LED AC220V 5W Dimmable LED …
OMNILUX OSD 250/2 94V/250W 1000h 8000K su Mondospettacoli …
7 inch LED Daymaker Headlight+4.5” Driving Fog Spot Angel …
10W 20W 30W 50W 100W LED SMD Chip Lampada Proiettore …
ISUZU OPTICS- Goniophotometer for lamps and small luminaire
ISUZU OPTICS- Goniophotometer for luminaire