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Mercury vapor lamp

  1. Aug 31, 2015 #1
    I've been reading up on mercury vapor lamps, which are often used as a light source in fluorescence microscopes. I still don't understand why it decreases the lamp's lifetime if you turn it on and switch it off without waiting 20 - 30 minutes. Is there a reason for this?
  2. jcsd
  3. Aug 31, 2015 #2

    Andy Resnick

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    Science Advisor
    Education Advisor

    This is called a 'hot restrike', and much higher voltages are required than the usual 'cold start'. For our arc lamps, we simply can't perform a hot restrike- the starter doesn't put out enough voltage. I'm not sure if a hot restrike decreases the lamp lifetime over and above normal operating cycles.
  4. Aug 31, 2015 #3


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    Staff: Mentor

    Do you need to wait 20-30 minutes for the lamp to heat up after you turn it on, or for it to cool down after you turn it off?
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