[RASMB] noisy interference data

[Borries Demeler]

> I have attached a jpeg image showing recent SV interference data plots
> taken from sedfit.
> 
> All data was collected with quartz windows as I was primarily interested
> in the absorbance @ 280 nm signal.
> 
> IP2 and IP6 are very noisy but IP4 looks fine.
> 
> Is this a calibration problem or is this related to damaged windows /
> centerpieces (there are no visible defects or scratches on any of the
> components).
> 
> Many Thanks,
> 
> Mark

Mark,

we had a similar symptom on our machine, turned out our drive was
bad and had to be replaced. You could notice a slight vibration in
the machine when it was running, that's what caused the problem in our
case. A bad vacuum pump could also cause vibration. There could also be
other causes for this problem, but I don't think it is related to your
cell components. Quartz windows will give you more time invariant noise,
but the spikes in your data are not time invariant, so it is not related
to that. Laser timing and alignment would be a couple of other things I
would check. For us, the problem was usually worse at lower concentration.

-Borries