A method of monitoring failure of an ultraviolet emitter in an ultraviolet disinfecting apparatus

摘要

An ultra-violet disinfecting apparatus comprising a plurality of UV emitters and a current control and monitoring module which monitors failure of UV emitters in the apparatus by sequentially energising each of the emitters, measuring current delivered to each or several of the emitters, comparing the current delivered to an expected reference value and identifying failure of one of the emitters when the combined current is different to the reference value. The UV emitters may be arranged in pairs. The UV emitters may comprise a bulb and ballast, and the current delivered may be measured using a current monitoring module placed between the ballast and bulb. Before the current deliver is measured, there may be a step of initiating the first pair of UV emitters and checking current is drawn to the expected ballasts. This step may be repeated for every pair of UV emitters. Checking against the reference may comprise checking whether the increase in drawn current is consistent with expected reference values. An error message which alerts the operator of a tube failure before or during irradiation when the combined current is less than the expected reference may be employed.