Evaluation method for light exposure levels for museum objects: Textiles case study

Abstract

Illuminance and exposure time are controlled to avoid rapid deterioration of museum objects. However, it is possible that the effect of harmful ultra-violet rapiation and visible light on objects is evaluated incorrectly by integrated illuminance. In this report, an evaluation method for light exposure levels for museum objects is discussed. Exposure tests of textiles with different light sources were conducted, and the progress of deterioration of the textiles was evaluated with two different light exposure level indexes: integrated illuminance and effective radiant exposure. The results show that effective radiant exposure can be used to evaluate light exposure levels causing damage to textiles more accurately. Furthermore, this paper proposes a new method that corrects illuminance and integrated illuminance. The new method easily improves the precision of evaluating light exposure levels with conventional integrated illuminance.