Hi,
a few month ago I made a question here, if it is better
to keep the temperature of the incoming or the temperature
of the outgoing air constant. The reason for this
question was simple. In spite of a high quality
proportional controller, which keepes the temperatur of the
outgoing air constant within a limit of +/- 0.1K I had
large variations of the incoming air temperature. Unfortunately
the electronic devices can see the incoming air
directly.
I got some recommendations, especially to keep
the temperature nearby the magnet constant.
Meanwhile the whole problem is solved. As often, the
solution is trivial. The reason for the variations of
the temperature of the incoming air was the room light.
We have fluorescent lights with an electrical power
consumption of alltogether about 2500 watts. This looks
very nice, but switching on all of the light decreases
the temperature of the incoming air by about 2.5K and
vice versa. As a consequence we have to keep the
light constant during a long time measurement and all
is fine.
Additionally we moved the sensor for the outgoing air
into that tube which gets the air from the top of the magnet.
Comprising we have a temperature stability of +/- 0.3K
now.
I want to thank once again all that people, who gave
helpful hints.
Rainer
Received on Fri Nov 08 2002 - 18:55:18 MST