Many patients are unsure of the duration of exposure after purchasing a UV phototherapy device. Do patients often consult that longer UV exposure time is better? Can the ultraviolet phototherapy device be irradiated every day? The similar issue of how many times a phototherapy device is irradiated per day.Everyone should be aware that all treatments are a gradual process without any shortcuts. How long does the UV phototherapy device last for once? How does the phototherapy device illuminate? Let's learn about it together.