When fixtures and lighting systems are tested under the IEC 60598, the ambient temperature is kept close to 25 degree centigrade and 65% relative humidity. After injecting the right voltage, the fixture is kept burning for four hours. In this time the temperature rise of the various components used in the fitting would have stabilized, and the temperature rise recorded through the help of thermocouples fixed to the various parts of the fitting. From this set of data, the release of the fitting is decided. If the fitting is found suitable for 25 deg. Ambient (Outdoor) and 35Deg. Ambient for indoor, it is cleared for sale, as the temperature in Europe never exceeds these temperatures. However, in other parts of the world, the temperatures are usually much higher.
- Fixtures are currently tested between 20°c and 30°c which is not adequate.
- Under the IEC 60598 [25°c, 65% RH], the fixture is lit for four hours until the temperature is stabilized.
- If the fitting is found suitable for 25°c [outdoor] and 35°c [indoor] conditions, it is cleared for sale.
- Europe rarely exceeds these conditions but other parts of the world do.