Deuterium lamp -hours life time?

First you need to ask yourself if your chromatography is still giving you satisfying results. If so, there's no need to replace the D2-lamp. Most people carry out an Intensity Test from LabAdvisor on a regular basis, so they can keep track of the intensity level. However, there are many more components in a UV detector contributing to intensity and they will all see some level of degradation over time. Therefore there might be a time when replacing the D2-lamp won't recover the intensity level to the expected level - similar to an engine: You keep changing the oil on an annual basis, but at some point, the engine needs a bit more care (e.g. minor=new spark plugs or major=new piston rings etc).

First you need to ask yourself if your chromatography is still giving you satisfying results. If so, there's no need to replace the D2-lamp. Most people carry out an Intensity Test from LabAdvisor on a regular basis, so they can keep track of the intensity level. However, there are many more components in a UV detector contributing to intensity and they will all see some level of degradation over time. Therefore there might be a time when replacing the D2-lamp won't recover the intensity level to the expected level - similar to an engine: You keep changing the oil on an annual basis, but at some point, the engine needs a bit more care (e.g. minor=new spark plugs or major=new piston rings etc).