Magnet-physik FH 55 - Zero

Gauss- / Teslameter
FH 55
BA - Nr.: 2000550EBA01
SEPTEMBER, 24
TH
, 2019
Page 19
5.4 Zero
The Zero function sets the display to zero. It is used to zero offsets of ambient low level field or
from the probe. Zero Probe is normally activated if the probe is placed in the shielding
chamber. It can also be activated with the probe outside of the shielding chamber to suppress
ambient magnetic fields, e.g. the earth magnetic field.
For best results, the instrument and probe should warm up for at least 5 minutes before zeroing
the probe, and at least 30 minutes for rated accuracy. The probe and the magnetic shielding
chamber should be at the same temperature.
When you push the Zero key, "Zero Probe" and "Press Enter to start" will be displayed. Place
the probe into the shielding chamber, that the probe tip is approximately in the middle. Do not
touch the end of the shielding chamber with the probe tip, some very sensitive probe may even
be damaged by this. Then press the Enter key to begin the zero probe routine. The unit then
automatically accepts whatever residual field it reads as a zero offset, forcing the display to
zero. The time needed for the zero routine depends on the number of ranges that are available
for the specific probe. It may take several seconds. Do not move the probe until the normal
display appears again.
Zero should be periodically executed, especially if the most sensitive ranges are used. If you
want to suppress large magnetic fields, you should use Relative instead of Zero.
The obtained zero setting remains stored for the probe if the instrument is switched off.
5.5 Filter
The Filter function is used to achieve a quieter reading. It makes the display better readable, if
the probe is exposed to a noisy magnetic field. Be careful, if Filter is switched on and changing
magnetic fields shall be measured, as peaks are evened out and the instrument reacts slower.
The Filter function of the FH 55 is configured, that slowly changing fields are displayed and
noise is suppressed.
5.6 Unit
The FH 55 displays the magnetic flux density (induction) B in Gauss (G) or Tesla (T) or the
magnetic field strength H in Ampere per Meter (A/m). With the Unit key you can select the
desired unit. Every push changes to another unit. Between the units and their multiples there are
the following relations:
Magnetic Flux Density B:
Magnetische Feldstärke H:
1T = 1000 mT = 1000000 µT
1 T = 10000 G
1 kG = 1000 G = 1000000 mG
1 kA/m = 1000 A/m = 10 A/cm
1 A/m = 0,001 kA/m = 0,01 A/cm
1 A/cm = 0,1 kA/m = 100 A/m
1 MA/m = 1000 kA/m = 1000000 A/m
The relation between the magnetic flux density B (in „Tesla“) and the magnetic field strength H
(in A/m) is given by the following relation:
B = µ
0
· H = 4 ·  · 10
-7
Vs/Am · H  1.257 · 10
-6
Vs/Am · H.