How do I protect archaeological collections from light damage?
Light can cause serious irreversible damage to archaeological collections. Light is a form of energy that causes fading and chemical breakdown of the materials from which an object is made. Light levels can be stated in terms of footcandles or lux. Footcandles are a unit of light produced by one candle at a distance of one foot, or the amount of light equal to one lumen per square foot. Lux is an international measurement of light equal to one lumen per square meter. One footcandle equals approximately 10 lux. Light causes damage to an object in proportion to its intensity and the exposure time. A light of 500 lux will theoretically cause the same amount of damage to an object in one year as a light of 50 lux will cause over ten years. Thus short exposure to a high lux level(e.g., 2500 lux caused by photographic or laboratory lights, or 200 lux for short exhibitions) need not cause undue damage over the total life of an object, provided this high exposure is compensated by a proportion
