Corrosion testing of LED-lights. What for? Aren’t LED garden lights something you just put up and let shine until it shines. Next year you buy a new set. Or?
Not at all. The Montejaur products belong to a different category and have a much higher demand. 2 years warranty is a necessity, however our customers shall be able to put up their light decorations every winter, year after year. The conditions are tough. There is winter, rain, snow, strong winds and the light nets raised 12 meters above ground. It is all about ensuring the products’ functionality during a time, when we need them the most.
Apart from plain mechanical endurance, corrosion is the biggest challenge. The LED-bulbs -actually they are not bulbs but diodes – are manufactured in a non stainless material. This is the main reason why many cheap LED-strings, Christmas lights and similar products are regarded as wear and tear products.
All Montejaur LED’s are encapsulated in a plastic sleeve. The sleeve is filled with a special glue creating a gas-tight environment where corrosion cannot take place. When Montejaur developed these products, tests were performed in corrosion chambers at the Swedish Research Institute, SP in Borås.
So how is a corrosion test performed then?
The tests are more advanced than you could perhaps imagine, and all parts of the testing cycle have its own ISO quality standard.
- A selected vital part of the LED light net is hung onto a plastic frame in a corrosion chamber.
- The light net is powered and exposed according to ISO 11997-1 Method B, which is a test cycle of 7 days.
- 24 hours of saltspray testing according to ISO 9227 NSS. The solution consists of highly refined vacuum salt (NaCl) with less than 0,001% copper and nickel. This is solved in deionized water with a conductivity less than 5µS/cm.
- 4 days of condensation testing according to DIN 50017KFW. This means 8 hours with 100% RH at 40°C followed by 16 hours of 75% RH at 23°C.
- 3 days of conditioning at 23°C and 50% RH
- The tests are completed with a visual inspection of corrosion and functional tests. In some cases isolation and microscope studies can be necessary. The reason for this is to separate discoloration due to solder flux from regular corrosion.