5. Description of the Instrument
Projekt Elektronik
MESS - UND REGELUNGSTECHNIK GMBH
page 13
The analog output is independent on relative measurement. It provides the instantaneous absolute
flux density value at any time.
5.13
Zeroing
The highly stable electronics of the FM 3002 and the many probe data it has stored in memory ensure
a zero setting which is precise and stable and easily repeatable.
Still, the zero setting should be checked and reset, if necessary, after some time.
To this end, the probe is introduced in a zero chamber; the instrument will show whether the zero
setting should be readjusted.
This can be done - for each of probes 1 and 2 separately - by means of the "zero" slotted trimmer
potentiometer on the rear panel of the FM 3002.
The zero setting should be checked also whenever the probe is changed.
Zeroing should not be carried out before an approx. 30 min warm-up period has elapsed.
5.14
Zero Chamber (Option)
Optional a zero chamber is attainable for our instruments.
The zero chamber is a one side closed pipe of good magnetic shielding metal to shield the existing
outer field. That is at least the earth magnetic field. In addition there may be other interfering fields from
the environment. In real world shielding may not be 100 %. A small residual magnetic field remains
inside of the zero chamber.
Fig. 4: zero chamber
5.15
Probes
Two different types of probe are offered: an axial probe and a transverse probe .
The connecting cable comes with a length of 2.80 m. Lengths up to 25 m are possible on demand.
Lengths greater than 2.80 m do not affect the accuracy and temperature specifications as the
instrument will be calibrated with the longer cable, so that the same high precision can be guaranteed.
