Transmitted irradiance not as expected in enclosed handheld minimal erythema dose device

摘要

To the Editor, In 2014, Turner and Goulden demonstrated that the ultraviolet B (UVB) irradiance from a handheld minimal erythema dose (MED) device varied depending upon the internal temperature of the device (1). The handheld MED device in question consisted of a single PL-S 9WV 01/2P narrowband UVB fluorescent lamp located inside a plastic handheld enclosure. On the treatment surface of the device, there were 10 apertures, each one containing attenuating foil to deliver a range of doses for a fixed exposure time. The link between temperature and irradiance led the investigators to recommend a shorter warm-up time for the device than had been previously advised.