Subject: Re: [sloan-25mlog 4483] 2.5m obslog 20190425 (SJD 58599)
From: John Downey
Date: Fri, 26 Apr 2019 07:12:00 -0600
>=20
> Notes:
> =3D=3D=3D=3D=3D=3D
> 1. Dust: The dust counter registered ~4.5K dust but we saw that pollen
> accumulated on car windshields. Please check the mirror. Thanks,
>=20
We'll check the mirror and probably clean even if not obviously dirty.
For general reference - new persons, anyone who has forgotten - pollen =
is generally too large to register on the dust counters.  Their upper =
limit is set mostly by the ability for particles to enter and be =
counted, and the larger particles usually do not make it through all the =
tubing attached to the counter.  Pollen is also sticky, making it less =
likely to be counted than other large particles.
The best way to keep an eye out for pollen from April through July is to =
look at the vehicle windshields as they did last night.  A note of the =
prevailing wind direction is also helpful, if its from the west the =
pollen is less likely to be a problem as the trees to the west are =
generally lower than the telescope.=