5
3
First Usage
3.1 Sensor filling and preparation
The sensor is shipped with empty inner volume, so the filling of the proton liquid is subject to the
end user. We recommend to use isopropanol or liquid paraffin, and to wear gloves and protective
glasses during the filling.
First of all, place the sensor upright on an even surface, with the cable outlet and the black locking
screw pointing upwards. Then open the sensor volume by loosening firstly the small securing screw,
and then the locking screw. Insert a funnel into the sensor opening and begin to pour the liquid
carefully. The sensor must be filled up to the point where the diameter of the inner volume shrinks
down for the first time, please see the following figure.
When filling is completed, the locking screw must be tightened sufficiently, such that the o-ring can
seal the inner volume. Finally, tighten the securing screw.
After preparation, the sensor should be placed outside in free space at least 50
cm above the
ground to avoid field gradients caused by minerals, stones etc. A plastic or wooden stand can be
used for this purpose. Ensure that no nails or other metals are used within such a stand. The axis
of the sensor should be aligned
such that the earth’s magnetic field lines are passing through the
sensor in a perpendicular
way. This will result in a maximum precession signal from the protons.
Of course, the first power-on can also be done within a building. However, in this case only the
general usage of the menus, the display etc. can be tried out. The measurements will probably
make no sense. Optionally, the connection to a PC can be tested. This connection can be used to
receive actual measurement values, to download saved data or to update the firmware of the
instrument. A stabilized 12V power-supply is sufficient in this case if it can deliver at least 2A of
current. For stationary use of the magnetometer in an observatory a high-quality laboratory power
supply with a low ripple and without high-frequency components is mandatory. This type of usage
requires great care of the ground connections. These are usually the most common case if the
measurements are disturbed and jumping around.
FLUID LEVEL
