- Zenith distance: < 75 degrees to avoid tipping mirror.
- Relative humidity: close the dome at 95% RH or earlier if necessary
to exclude any and all moisture from the dome. In particular be alert
for sudden and unexpected fog formation and do not leave the vicinity
of the dome if it's open without being very alert for any sudden
change in the weather. If you can see moisture in your flashlight
beam, or if wooden surfaces and papers get wet; close!
- Wind: no explicit limit, but when leaves and twigs start blowing in
perhaps you're pressing too hard. Usually before that happens, the
tube will shake too much for reliable observations anyway.
|