Functions; Ac/Dc; Range; Auto - Magnet-physik FH 54 Operating Instructions Manual

Gauss- / Teslameter FH 54

5 Functions

In the present chapter all functions of the FH 54 are described in detail. The most important
functions can be accessed directly over function keys. Some rarely used function can be
invoked in a menu. This main menu is accessed with the Mode key. The submenus are selected
with the arrow keys (, ) and opened with the Enter key.

5.1 AC/DC

With this key the user can select between AC (periodically alternating) and DC (static)
magnetic field measurement. Every push changes to the other field type.
A DC magnetic field is for example generated by a permanent magnet or by a DC current
flowing in a coil. An AC magnetic field is generated by an AC current in a coil.
In DC-mode the static magnetic field value is shown together with sign and unit. The value can
also be read from the serial interface and the analog output.
In AC-mode the RMS (root mean square) value of the field strength or flux density is displayed
unless the Peak key is not pressed (see below). The AC RMS reading is a measurement of true
RMS, defined as the square root of the average of the square of the field function taken through
one period. A DC component will be rejected if it is not large enough to overload the selected

range.

When changing to AC or DC, previously established Relative and Limit setpoints are
maintained.
The functions Max./Min. and Peak are switched off when changing to AC or DC, as they
operated different in both modes.
5.2 Range
Pressing the range key opens a menu that allows to select one of ranges that are available for
the connected probe. The actually selected range is shown inversely. Select the desired range
with the arrow keys. Press Enter to confirm your choice or press Escape to return to the
previously selected range.

5.3 Auto

By pressing Auto, the Auto Range mode can be activated. In this mode, the FH 54 selects
automatically the range with the best resolution for the field to be measured. It can take up to 2
seconds for Auto Range to work, so manual ranging may be better in some conditions.
Auto cannot be used together with the functions Peak and Max./Min..
Auto Ranging should not be used when measuring small fields in large background field, i.e.,
measuring a small DC field in presence of a large AC field, or measuring a small AC field in
the presence of a large DC field.
TH
BA - Nr.: 2000540EBA01 S , 24 , 2019 Page 19
EPTEMBER