Many lab measurement equipment for analog, radiou and RF purposes, such as frequency counters, arbitrary signal generators, oscilloscopes, etc. have the option to input an external reference clock (almost always 10 MHz, though some micro/mm-wave equipment is switching to a higher frequency reference).
From what I know, using this has two advantages:
It allows me to lock different instruments to each other - if my synthesizer and spectrum analyzer are using the same 10 MHz reference clock, they will relative to each other have no error except for their own internal jitter. This can be very useful since it removes (well, significantly reduces) uncertainty in my measurements.
A second advantage is that this allows me to use a very high-performance clock and share it over multiple instruments, instead of needing a very high performance clock in every instrument.
This brings me to my question:
If I have a lab with multiple devices, (why) would I still want a separate precision timebase (such as a TCXO) in every instrument, instead of just getting a stand-alone reference and provide all of my instruments with this reference?
(Ofcourse, we assume that all our gear can take an external reference clock. I think that this is possible with almost all modern gear that needs a timebase and thus a valid assumption)