When a mercury vapour black light is inadvertently cut off, approximately how long should it be allowed to cool before attempting to restart?

Related MCQs

• If a mercury vapour arc black light is inadvertently turned off, how soon may it be restarted?
• What minimum warm-up time is required for acceptable performance of a mercury Vapour arc black light?
• The output of a mercury vapour black light depends on:
• When a mercury vapour black light is first turned on, what minimum warm-up time is normally required?
• For adequate test results, the black light used in fluorescent penetrant examination should provide what minimum black light intensity at the test surface?
• Mercury vapour black lights may be extinguished if the supply voltage drops below about:
• What action is necessary if the penetrant is inadvertently allowed to dry on the test piece?
• While performing a fluorescent water washable penetrant test, which of the following steps should be performed under black light?
• The radiation from 37 GBq (1 Ci) of Co-60 (0.145 Gy or 14.5R at 30.5 cm or 1 foot) is attenuated in air to approximately 5mR/h at a distance of approximately:
• What is the likely result of looking directly into a black light?