Subject: Re: [sloan-25mlog 6337] 2.5m obslog 20221109 (SJD 59893)
From: John
Date: Thu, 10 Nov 2022 15:06:41 -0700
> On Nov 10, 2022, at 5:55 AM, dmbiz@apo.nmsu.edu wrote:
>=20
>=20
>                       APACHE POINT OBSERVATORY SDSS 2.5M
>=20
>                                 OBSERVING LOG
>                          Wednesday November 09, 2022
>=20
>                                  (SJD 59893)
>=20
>=20
> - the upper FPI fiber gives lower flux than usual. We'd like to =
request its  =20
>  visual inspection and cleaning in the day time. w-43310074 5  A =
DomeFlat
FPI fibers cleaned again today.  This time I whittled down a Sticklers =
swab to fit in the upper FPI socket and cleaned with their solvent & =
instructions.  If this does not work I may do the same tomorrow with an =
alcohol instead.  What I tried yesterday was just squirting some of the =
solvent into the socket when I found the swab was too large for the =
socket (it=E2=80=99s about a 3mm stiff swab).
Something looks odd inside the female FPI connectors (FPS side) to me.  =
They are difficult to inspect due to design and placement, but it almost =
looks like before polishing both fiber ferrules were marked with a =
sharpie.  I could imagine doing this while terminating the fibers to =
keep an eye on cutting too deep when polishing.  But that is just a wild =
guess.
We did occasionally have trouble with marker ink flaking off and getting =
onto a fiber when plugging plates (that is why I will try alcohol =
tomorrow).  I think in this case contamination with dust or a flake of =
skin is more likely.
We also are ordering the correct diameter Sticklers swab for this task.=20=