Purchasing LED llights should be noted that the problem (2)
On the light angle. Light-emitting different lighting angle is different, rather special point of need:
Manufacturers of small batch, then the price will naturally be higher. - the total light on life. LED light life is a bad decision by the 'made ??of different materials! Will result in a different light decline. Some low-quality LED has been used for some time down the basic dark or bright. LED light source and good should decline significantly darker after 5 years, down about 70% of the original brightness.
Here the United States recommend the use of lighting design industry, purchasing LED light should be asked questions' for reference.
① Please make certified by a qualified laboratory test reports issued by 'include files and the complete optical properties
LM-79 and LM-80 test results.
② your product has been made in the Energy Star mark or pending?
③ your product is ENERGY STAR CALIPER plan tested?
④ you sign "Quality advocates Pledge" (the quality of advocacy Convention)?
⑤ whether you are adding "Lighting Facts Led Product" (real LED lighting products)?
⑥ Please provide for each product "Lighting Facts (lighting real value) label.
⑦ for each product, please answer the following questions.
When the maximum operating temperature junction temperature for the most number of Gao?
Operational temperature range from how much?
ASTM B117 salt spray test whether (outdoor lighting), during long?
Lamp lumen maintenance rate?
"What kind of lighting used within the LED? label what? is in accordance with IESNA LM-80 test?
"expected lamp life and warranty terms?
"How waterproof rating?
'How Power Factor?
'lamp does not light up when turned off the power to consume?
"Whether a person or other safety certification mark? (Please provide certified documents)
'How the color temperature specifications?
'How long-term stability of the light and color?
"How the error value of each mark?
"whether the product or meet the RoHS lead-free requirements?