When to change a light bulb

In my research, I often make use of an instrument called a stopped flow. In a nutshell, this instrument allows rapid scanning in order to measure kinetics of a reaction. This is sort of the bread and butter of our lab.

This instrument is also the bane of my existence. It is an old instrument. It still uses DOS software to collect and analyze data. It crashes and misbehaves more often than I care to count. From time to time I will even refer to it as "Satan".

Twice this year the Xenon light bulb exploded in it. One time it was even a bit dramatic in that smoke started to come out of the instrument. Fortunately, the Xenon bulb is in a metal encasement, but it is open in various places, so when it explodes, glass pieces come flying out. But, after all, there is a warning on it: May Explode.

Do to this fact, one always wears protective gear when working on this instrument.

However, now the running joke in my lab is:

How do you know when to change the Xenon light bulb? When it explodes!