Hi all,
Everyone seems to have decided that the problem is electrical, but ...

You didn't say where you are located. In the southwest desert one must pay 
attention to the heating effects of the sun:<)

I had placed a seismo in a building at our school, but, unfortunately, it 
was against the south wall of the building. The 40-50F temp change between 
day and night caused a very nice shift in the zero point each day. The 
whole building was heating up and tilting! Moving to another location 
solved the problem.

When you hear the thunder of hooves, think horses, not zebras.

Darrell


__________________________________________________________

Public Seismic Network Mailing List (PSN-L)