Magnet-physik FH 52 User manual

BA - Nr.: 1620010102
Emil-Hoffmann-Strasse 3
50996 Koeln
Germany
Operating Instructions
FH 52
Gauss-/Teslameter
Preserve for future application!

Gauss-/Teslameter
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Introduction
Dear customer,
You have decided on a product of high technical standard from MAGNET-PHYSIK. We are
convinced that our product will be a valuable help in your daily work. Condition is that the
operating instructions are read carefully and are observed. We will not take over any warranty
or liability in case of deliberate faulty operation or disregard of our safety notes.
If you face any problems while working with the equipment or the operating instructions or if
you have any proposals for improvements please do not hesitate to contact us.
Purpose
The user's manual gives a survey about the applications and functionality of the FH 52
Gauss-/Teslameter.
Target Group
In the following chapters the user of the equipment will find all necessary information
regarding the handling of the product or device.
Manufacturer
MAGNET-PHYSIK,
Dr. Steingroever GmbH
Emil-Hoffmann-Str. 3
50996 Koeln
Germany
Tel. [phone] / 3919-0
Fax. [phone] / 3919-19

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Notes
•This instruction cannot cover every possible aspect of installation, operation and
maintenance, or every error that might occur.
•If you would like more information, or if you encounter particular problems that are not
discussed in sufficient detail in the instructions, please contact company MAGNET-
PHYSIK.
•We also state that the content of these Instructions is not part of a previous or existing
agreement, undertaking, or legal relationship, and is not intended to amend the same. All
obligations of MAGNET-PHYSIK result from the applicable warranty: These contractual
warranty provisions are neither extended nor limited by statements in these instructions.
MAGNET-PHYSIK GmbH, Köln - 1620010102/2016
Passing on and reproduction of these documents, and utilization
and disclosure of their contents is prohibited unless specifically
authorized. Violations shall be cause for damage liability.
All rights reserved.
Subject to change without prior notice
Although the contents of this publication have been checked for
agreement with the hardware and software described, we do not
accept liability for total agreement since differences cannot be
completely excluded. The information in this publication is
checked at regular intervals and necessary corrections included in
the next release. Your suggestions for improving this publication
are welcome.

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Table of Contents
1General Information ....................................................................................................6
1.1 Safety Instructions ...............................................................................................6
1.2 Intended Purpose of Operation ............................................................................6
1.3 Sources of Danger................................................................................................7
1.4 Authorized Operators...........................................................................................8
1.5 Safety Measures at Place of Installation..............................................................8
1.6 Safeguard Installations.........................................................................................8
1.7 Emergency Measures...........................................................................................8
2Transport and Installation...........................................................................................9
2.1 Unpacking and Checking.....................................................................................9
2.2 Transport and Storage..........................................................................................9
2.3 Technical Data.....................................................................................................9
2.4 Installation ...........................................................................................................11
2.5 Structure of the Device ........................................................................................12
2.6 Accessories (included in delivery).......................................................................12
2.7 Options (to be ordered separately).......................................................................13
2.8 Taking Into Operation..........................................................................................13
3Operation.......................................................................................................................14
3.1 Display.................................................................................................................14
3.2 Key Pad................................................................................................................15
3.3 Functions..............................................................................................................16
3.3.1 On/Off Key –Switching the Device On and Off ............................................16
3.3.2 Range Key –Range Selection .........................................................................16
3.3.3 Zero Key –Zeroing the Probe.........................................................................17
3.3.4 Reset Key –Resetting the Display of Maximum and Minimum ....................17
3.3.5 Menu Operation...............................................................................................17
3.3.6 Main Menu ......................................................................................................18
3.3.7 AC/DC Menu...................................................................................................18
3.3.8 Unit Menu........................................................................................................18
3.3.9 Filter Menu ......................................................................................................19
3.3.10 Max./Min. Menu..............................................................................................20
3.3.11 Limit Menu......................................................................................................20
3.3.12 Relative Menu..................................................................................................21
3.3.13 Information Menu............................................................................................22
3.3.14 Display Menu ..................................................................................................23
3.3.15 Power Off Menu..............................................................................................23
3.3.16 Test Menu........................................................................................................24
3.3.17 Measuring Data Memory.................................................................................24
3.4 Switching between Battery Power and USB Power............................................25
3.5 Standby Mode......................................................................................................25
3.6 Battery State Indicator .........................................................................................25

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3.7 Probes...................................................................................................................26
3.7.1 Probe Handling................................................................................................27
3.7.2 Polarity of the Magnetic Field.........................................................................28
3.8 Remote Operation................................................................................................29
3.9 Operating Principle..............................................................................................29
4Maintenance..................................................................................................................31
4.1 Maintenance Plan.................................................................................................31
4.2 Checking for Damage..........................................................................................31
4.3 Calibration ...........................................................................................................31
4.4 Troubleshooting...................................................................................................31
4.5 Taking Out of Operation......................................................................................32
List of Tables
TABLE 1: SPECIFICATIONS ..............................................................................................................9
TABLE 2: AMBIENT CONDITIONS ..................................................................................................10
TABLE 3: RANGES.........................................................................................................................16
List of Illustrations
FIG.1: FRONT VIEW OF THE DEVICE..............................................................................................12
FIG.2: DISPLAY DURING MEASUREMENT OPERATION ...................................................................14
FIG.3: MAIN MENU.......................................................................................................................18
FIG.4: AC/DC MENU....................................................................................................................18
FIG.5: UNIT MENU........................................................................................................................19
FIG.6: FILTER MENU.....................................................................................................................19
FIG.7: MAX./MIN.MENU..............................................................................................................20
FIG.8: LIMIT MENU.......................................................................................................................21
FIG.9: RELATIVE MENU................................................................................................................22
FIG.10: INFORMATION MENU .......................................................................................................23
FIG.11: DISPLAY MENU................................................................................................................23
FIG.12: POWER OFF MENU ...........................................................................................................24
FIG.13: TEST MENU......................................................................................................................24
FIG.14: TRANSVERSE PROBE ........................................................................................................26
FIG.15: AXIAL PROBE...................................................................................................................26
FIG.16: PROBE ORIENTATION FOR POSITIVE MEASUREMENT AND POLARITY DISPLAY “N”...........28
FIG.17: OPERATING PRINCIPLE OF A HALL GENERATOR...............................................................30

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1General Information
The Gauss-/Teslameter FH 52 is a measuring instrument for the quantities “Magnetic Field
Strength” and “Magnetic Flux Density” or “Magnetic Induction”.
The following instructions with regard to use and operation must be strictly adhered to. The
user or operator of the equipment must make sure that only suitably qualified personnel
operates or services the device.
1.1 Safety Instructions
Special warnings, whose non-observance may lead to injuries and/or property damage, as well
as important hints, are indicated in these operating instructions as follows:
Danger!
Means that serious bodily injury resulting in death or considerable material
damage may occur if the appropriate safety measures are not taken.
Warning!
Means that bodily injury or material damage may occur if the appropriate
safety measures are not taken.
Important!
Indicates important information that is to be paid particular attention.
1.2 Intended Purpose of Operation
Important!
It must be explicitly stated that the FH 52 is to be used only for its intended
purpose.
The intended purpose of the FH 52 is the measurement of the magnetic
field strength or the magnetic flux density of static or periodically
alternating magnetic fields.
Every application not in accordance with this intended purpose is prohibited
and implies the deliberate dealing with non-calculable risks for both the
operator as well as the equipment. Unauthorized reconstructions of and/or
alterations to the equipment are forbidden for safety reasons!

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1.3 Sources of Danger
The FH 52 is operated with battery power. For reasons of work-place safety and accident
prevention the sources of danger emanating from the use of the device will be pointed out here.
The respective instructions to the operator and owner of the FH 52 are to be strictly adhered to.
Danger!
Do not operate the instrument in an explosive atmosphere. Do not operate it
in the presence of flammable gases or fumes. Operation of any electrical
device in such an environment constitutes a definite safety hazard.
Danger!
The measuring instrument and the software of this product are not designed,
tested, intended or authorized for use in any medical applications, surgical
applications, medical device manufacturing or any similar procedure or
process. Disregard of this limitation can cause danger to life.
Danger!
The Hall probe must never be brought into contact with an electrical
voltage conductor or close to an electrical high voltage conductor. The
coating or sleeve on the probe surface is not an electrical insulation with
defined properties. Disregard of this warning can cause danger to life of the
user. Additionally the measuring instrument and a connected computer can
be damaged.
Warning!
Although the FH 52 is protected against splashes, it is not waterproof.
Therefore it must not be immersed in water or permanently exposed to
conditions of high humidity.
The device must not come into contact with liquid media, like water, oil,
etc. If, in spite of all precautions taken, a liquid should get into the FH 52,
there is a considerable risk for the operation of the device. In this case the
device must be switched off immediately and the USB cable and the
batteries must be removed.
The device must be switched off when being cleaned. Never clean it with
water. Only use a dry cloth for cleaning!

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Warning!
Keep away from live circuits:
Operating personnel must not remove instrument covers, except the cover of
the battery compartment. Only qualified maintenance personnel must make
component replacement and internal adjustments. Do not replace compo-
nents with the USB cable connected.
Warning!
Do not substitute parts or modify the instrument:
Due to the risk of electrostatic discharge and because of the danger of
introducing additional hazards, do not install substitute parts or perform any
unauthorized modification to the instrument. Return the instrument to
MAGNET-PHYSIK Dr. Steingroever GmbH, Cologne, Germany or an
authorized representative for service and repair to ensure that safety features
are maintained.
1.4 Authorized Operators
The FH 52 must only be used by personnel authorized by the owner.
In this case the owner must:
•place operating instructions at the operator’s disposal at all times and
•make sure the operator has read and understood them.
1.5 Safety Measures at Place of Installation
No special safety measures are necessary.
1.6 Safeguard Installations
The device does not have any special safeguard installations as safety concerns have been taken
into account in construction. A potential danger only arises if the device is used against its
intended purpose of operation or safety regulations are disregarded.
1.7 Emergency Measures
In the case of emergency, when all safety instructions fail, proceed as follows:
Important!
1. Take emergency measures, such as “First-aid”.
2. Secure the device and working place against further use.
3. Write the case report.

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2Transport and Installation
2.1 Unpacking and Checking
Check the packaging for signs of damage. Any correspondence regarding damage (evident or
hidden) or partial loss of the consignment must be made in written form immediately after
receipt of goods. Also inform the freight forwarder immediately.
Open the packaging. A packing list is enclosed which enables you to check that the ordered
device and accessories have been received. Use the packing list to check that all parts of the
device have been unpacked. Check them for damages. Make sure everything has been removed
before discarding the packaging.
If the device has been damaged in transit, make sure the forwarder and insurance are informed.
Inform Magnet-Physik of the same. If there are parts or accessories missing, let Magnet-Physik
know immediately. Magnet-Physik cannot accept responsibility for any missing parts if not
informed within 60 days from date of dispatch.
Important!
Check on receipt of goods and before taking the device or accessories into
operation whether they show visible signs of damage. The device must
otherwise not be put into operation before being cleared by an authorized
person.
2.2 Transport and Storage
Always use suitable packing or containers for transport and storage, so that damage is avoided.
Store the instrument in the hard case in which it has been delivered.
Do not store the device in places where one or more of the limiting values for the ambient
conditions are exceeded.
2.3 Technical Data
Table 1: Specifications
Display
3½ digits (0...±1999), backlight when powered from USB
Units
Tesla (T), Gauss (G), Ampere per Meter (A/m), Ampere per
Centimeter (A/cm), Oersted (Oe)
Ranges (with standard
probes)
20 mT
200 G
16 kA/m
160 A/cm
200 Oe
200 mT
2 kG
160 kA/m
1600 A/cm
2 kOe
2 T
20 kG
1600 kA/m
16 kA/cm
20 kOe
Resolution (in most sensitive
range, with standard probes)
0.01 mT, 0.1 G, 0.01 kA/m, 0.1 A/cm, 0.1 Oe
Frequency range
DC (with polarity display +/- or N/S)
AC 20 Hz - 10 kHz (true rms)

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Accuracy (instrument with
standard probe, at 23 °C)
DC: 1 % of reading + 0,05 % of range
AC ≤ 5 kHz: 3 % of reading + 0,25 % of range
AC > 5 kHz: 5 % of reading + 0,25 % of range
Precision (reproducibility),
(instrument with standard
probe, at 23 °C)
DC: 0,5 % of reading + 0,05 % of range
AC: 2 % of reading + 0,25 % of range
Temperature Coefficient of
Sensitivity (instrument with
standard probe)
Approx. -0,05 %/K
Sampling rate
Standard 4.17 Hz, at USB operation up to 16.7 Hz
Power source
- Battery life time
- Current consumption
Exchangeable batteries, 4 pcs. 1.2 V to 1.5 V, size AA (LR6)
or power supply from USB
Approx. 300 hours with high quality alkaline batteries
Approx. 165 mA from USB, approx. 6 mA from batteries
Accessories/Options:
- Hall probes
Transverse probe or axial probe;
the probe connection cables are fixed to the probes,
length 1.5 m (5 ft);
- Hard case
Included
- USB cable
USB type A to micro USB type B,
length approx. 1.8 m (6 ft)
- Magnetic shielding chamber
Optional, see data sheet “NK Shielding Chambers”
- USB AC adapter
Optional, different AC line plug styles available
Outer dimensions
228 mm x 70 / 117 mm x 47 mm
Weight
approx. 0.4 kg
Table 2: Ambient Conditions
Temperature:
- for operation
0 °C to +40 °C (the FH 52 can be operated
from -10 °C to +40 °C, but AC accuracy
is not specified below 0 °C)
- for storage and transport
Class 1K4 according to EN 50178
-25 °C to +55 °C
Relative humidity:
- for operation
Class 3K3 according to EN 50178
5 % to 85 % (indoor), no dew,
1 g/m3to 25 g/m3
- for storage and transport
Class 1K3 according to EN 50178
5 % to 95 % (indoor), no dew,
1 g/m3to 29 g/m3

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Air pressure
- for operation
Class 3K3 according to EN 50178
86 kPa to 106 kPa
- for storage and transport
Class 2K3 according to EN 50178
70 kPa to 106 kPa
Pollutants:
- SO2
0,5 ppm
(rel. humidity 60%, no dew)
- H2S
0,1 ppm
(rel. humidity 60%, no dew)
Oscillations:
according to IEC 68-2-6
10 ... 55 Hz (const. amplitude 1.0 mm),
57 ... 150 Hz (const. acceleration 2 g)
Immunity from discharge of static electricity:
based on IEC 61000-4-2
Air discharge: 8 kV
Contact discharge: 4 kV
Immunity from electromagnetic HF field,
amplitude modulation:
based on IEC 61000-4-3
80 MHz to 1000 MHz
3 V/m
80 % AM (1 kHz)
Immunity from electromagnetic HF field,
pulse modulation:
based on IEC 61000-4-3
(900 5) MHz
3 V/m
200 Hz repetition frequency
Regulations regarding immunity from electromagnetic fields of power line frequency are not
applicable as the device is a measuring instrument that is measuring in this frequency range.
2.4 Installation
Important!
Never store or operate the device in places where one or more of the
limiting values for the ambient conditions are exceeded.

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2.5 Structure of the Device
Fig. 1: Front view of the device
The FH 52 Gauss-/Teslameter is a hand-held measuring instrument that provides measurements
of AC and DC magnetic fields. The device is designed for wide range, high accuracy, and ease
of use. User interface are front panel keys and a liquid crystal display (LCD). Most important
user features are only one pushbutton away.
In Fig. 1, the front side of the FH 52 is shown. The sockets on the upper side are used for probe
and USB connection.
2.6 Accessories (included in delivery)
The field strength meter is provided with the following accessories:
•Carrying and storage case: a hard case is provided.
•One probe is included in the delivery.
•One set of size AA batteries (4 pieces).
•USB cable (USB type A to Micro-USB type B)
•Operating instructions.

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2.7 Options (to be ordered separately)
The following parts are optionally available for the FH 52:
•Further probes, see also chapter 3.7
•Shielding chamber: a small chamber in which the tip of probe is placed to eliminate
background magnetic fields like the earth's magnetic field during zeroing.
•AC adapter with USB connector (different power line connector styles are available).
2.8 Taking Into Operation
To take the FH 52 into operation, please proceed as follows:
1. Install the batteries: Open the door on the bottom side of the FH 52. Install 4 batteries
observing the polarity for each cell into the battery compartment. Close the door again.
2. Connect the probe: Plug the probe into the socket on the top face of the measuring
instrument. An arrow on the top side of the plug housing indicates the proper plug
position. You can remove the probe again by pulling the plug. Do not try to twist the
plug.
3. Switch on the device: Press the On/Off key. First the Magnet-Physik logo and the
device name appears. Then the device returns into the operating condition in which it
was when switched off.
The FH 52 should always be switched off before a USB power supply (AC adapter) is
connected or removed. For details see chapter 3.4.

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3Operation
The FH 52 is a measuring instrument that allows measuring the magnetic flux density or
induction Band the magnetic field strength Hof static or periodically alternating fields. The
instrument is characterized by a large measuring range, high accuracy and easy operation. It is
operated via keys or the USB interface. The measured values, information about the operating
conditions and the menus are shown on a liquid crystal display.
The display content depends on the selected language. The devices are delivered with the
language setting “English”. The language can be changed in the Display menu (chapter 3.3.14).
The following figures show the English displays.
The most important functions are invoked by the touch of a key. Further settings can be carried
out in a menu that is opened using the Mode key. The settings are automatically saved when
the device is switched off.
3.1 Display
The figure below shows the measurement display of the FH 52 with all available elements
enabled. In real operation you will normally use only some functions and the displayed
information will be less complex.
Fig. 2: Display during measurement operation
In measurement operation, the actual reading is shown in large characters in the center of the
display. The numerical value is displayed with 3½ digits at maximum, followed by the unit. If
an overrange condition occurs, the reading will flash.
If the Max./Min. function (chapter 3.3.10) is enabled, the values captured using this function are
shown in the line below the reading.
Below a separator line is shown, or if the Bargraph function is switched on, a horizontal bar
whose length is proportional to the measured value.
The following information is shown in the two lower lines:
1. Signal mode: DC or AC (measurement of static or alternating fields).
2. Range: Auto, if automatic range selection is enabled and the upper range limit of the
currently selected measuring range.

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3. State of the limit comparator: Low,OK,High. Therefore the Limit function must be
enabled.
4. If the Filter function is enabled, the term Filter is shown.
5. Rel.: The reference value for a relative measurement. Therefore the Relative function
must be enabled.
If the Polarity display is enabled, the polarity of the magnetic field is indicated by a large Nor
Sbehind the measured value. More information regarding this point is given in chapter 3.7.2.
The symbol
c

is shown behind the reading if the displayed value is outside the calibrated range
of the probe. This is never the case for standard probes.
Readings that are stored in the measured data memory are shown in the upper left corner of the
display together with their sequential number. The unit behind the actual reading also applies to
these values.
If the FH 52 is set to remote mode via the USB interface, an Ris shown in the upper right
corner. In remote mode, the operation using the key pad is restricted.
3.2 Key Pad
The key pad consists of an integrated block of 9 keys and a line arranged above with 3 keys.
The block contains the following keys: On/Off, Delete, Mode, Escape, Enter and arrow
keys in 4 directions. The line contains the Range, Zero and Reset keys.
Short descriptions of the key functions are given below. Detailed information on the functions
is provided in the next chapters.
On/Off The instrument is switched on and off using this key.
Mode With this key you can switch between the measurement display and the menu
display. If the Mode key is pressed in a submenu, the current selection is
accepted and the measurement display is activated.
The arrow keys and the Enter and Delete keys have different functions, depending on whether
the measurement display or a menu is active.
In the measurement display:
Enter Saves the current reading to the measured data memory. The saved value is
shown in the upper left corner of the display.
←, →, ↑, ↓The arrow key are used for navigation in the measured data memory.
Delete Deletes the value that is shown in the upper left corner of the display from the
measured data memory. The remaining values are renumbered in ascending
order.
In a menu:
Enter Using this key the selected submenu is invoked or inputs that are shown in the
display are accepted.

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←, →, ↑, ↓The arrow keys are used to move the selection mark. The selection is shown
inverted.
Escape This key is used to cancel an input and to return to the previously set values.
Using the Range, Zero and Reset keys, frequently used functions are carried out immediately.
Range Pressing this key multiple times allows switching between the available
measuring ranges and the automatic range selection (Auto).
Zero Starts the automatic zero adjustment.
Reset Resets the stored maximum and minimum values.
3.3 Functions
3.3.1 On/Off Key –Switching the Device On and Off
Press the On/Off key to switch on the instrument. First the logo of Magnet-Physik and the
device name are shown. Then the device returns to the state it was in before being turned off.
The device cannot be switched off again until the logo has disappeared.
To switch off the device, press the On/Off key again. Before the device powers down, all
eventually changed settings and changes to the measured data memory are copied from the
volatile to the no-volatile memory. Therefore you should always switch off the device using the
On/Off key. If the device does not contain operational batteries and the USB cable is removed
while the device is on, settings or measured data can be lost.
Settings and changes to the measured data memory are also copied from the volatile to the no-
volatile memory when the device enters the standby mode (chapter 3.3.17).
3.3.2 Range Key –Range Selection
Pressing this key multiple times allows switching between the available measuring ranges and
the automatic range selection (Auto). The available measuring ranges depend on the selected
unit and are given in the following table.
Table 3: Ranges
20 mT
200 G
16 kA/m
160 A/cm
200 Oe
200 mT
2 kG
160 kA/m
1600 A/cm
2 kOe
2 T
20 kG
1600 kA/m
1.6 kA/cm
20 kOe
In Auto mode, the FH 52 automatically selects the range with the best resolution for the value
to be measured. It can take about 1 second until the range is set. Besides the device switches
already at 90 % of the upper range limit into the next higher range and it returns at 7 % of the
upper range limit into the next lower range. So manual ranging might work better under some
conditions, especially if the reading is close to the upper range limit.

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3.3.3 Zero Key –Zeroing the Probe
The Zero function is used to null the display. The purpose is to cancel out small magnetic fields
and probe offsets. The zero routine is normally initiated while the probe is outside the magnetic
field to be measured:
(a) Place the probe outside the magnetic field to be measured and start zeroing by pressing
Zero.
(b) Zeroing can also be carried out when the probe is located inside the optional shielding
chamber. Therefore carefully place the tip of the probe about in the center of the
chamber. Do not move the probe to the rear end and do not touch the end face of the
chamber with the probe tip. Then press the Zero key.
The zeroing routine can take a few seconds. Do not move the probe until the normal display
appears again.
For best measurement results periodic zeroing of the probe is commended, especially if the
most sensitive range is used. If you want to suppress large magnetic fields, you should use the
Relative function instead of Zero.
3.3.4 Reset Key –Resetting the Display of Maximum and Minimum
Using the Reset key, the memories for the maximum and minimum measured values are reset
to the current reading.
The FH 52 allows capturing the maximum absolute reading, the maximum and minimum, and
the difference between maximum and minimum. For details see chapter 3.3.10.
3.3.5 Menu Operation
In the single menus the title is shown in the first line. Below it is indicated which keys can be
used for inputs. The keys Enter, Mode and Escape are nearly always available. These keys
have the following functions:
In the main menu you open the selected submenu by pressing Enter. In a submenu you
complete the current input with Enter and move to the next line. If there are multiple input lines
in a submenu, each input has to be confirmed with Enter. Following the last input in a submenu
you leave it with Enter and return to the main menu.
By pressing the Mode key you will return immediately from the main menu or a submenu to
the measurement operation. For submenus the last input or selection is accepted.
Using the Escape key, you can go back one step in operation without accepting the latest
input.

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3.3.6 Main Menu
The following menus can be invoked from the main menu:
Fig. 3: Main menu
3.3.7 AC/DC Menu
In the AC/DC menu you can choose whether you want to measure static (DC) magnetic fields or
periodically alternating (AC) fields. Make your choice using the arrow keys and finish the input
with the Enter or the Mode key.
Fig. 4: AC/DC menu
If AC is selected, the root mean square (RMS) value of the field strength or flux density of a
periodically alternating magnetic field is displayed.
If DC is selected, the measured value for a static magnetic field is shown. The sign gives the
field direction according to the definition in chapter 3.7.2. Additionally the polarity can be
shown with the characters N(for North) and S(for South), see chapter 3.3.14.
3.3.8 Unit Menu
The FH 52 shows the magnetic flux density or induction Bin Tesla (T) or Gauss (G) or the
magnetic field strength Hin Kiloampere per Meter (kA/m), Ampere per Centimeter (A/cm) or
Oersted (Oe).

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Fig. 5: Unit menu
Between the units and their multiples there are the following relations:
Magnetic Flux Density B:
Magnetic Field Strength H:
1T = 1000 mT
1 T = 10000 G
1 kG = 1000 G
1 G = 0.001 kG = 0.0001 T
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 Oe = 0.001 kOe
1 A/m = 4/103Oe 0.01257 Oe
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= µ0· H= 4 · · 10-7 Vs/Am · H1.257 · 10-6 Vs/Am · H.
Here µ0is the magnetic field constant or permeability of the vacuum.
If the unit for the measurement is changed, the relative and limit set points and stored measured
values are automatically converted to the new unit.
3.3.9 Filter Menu
The Filter function averages several sequential field readings (moving average). It is used to
quiet the display, making it more readable when the probe is exposed to a noisy field.
Fig. 6: Filter menu
Filtering slows down the reaction on changes of the field strength. Therefore care must be
taken, especially if filtering is used together with the Max./Min. function.

Gauss-/Teslameter
FH 52
BA - Nr.: 1620010102
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3.3.10 Max./Min. Menu
The Max./Min. function allows capturing maximum and minimum values.
Fig. 7: Max./Min. menu
If Absolute is selected, the maximum is shown in the line below the measured value. The
maximum is the highest reading that was captured since the Reset key was pressed last. When
this maximum is evaluated, the sign of the reading is not taken into account.
If Max./Min. is selected, the maximum, the minimum and the difference between maximum and
minimum are shown in the line below the actual reading. The maximum is the highest reading
that was captured since the Reset key was pressed last. The minimum is the lowest reading that
was captured since the Reset key was pressed last. Here in DC mode the sign of the readings is
taken into account.
The Reset key deletes the captured values. These are also reset if the device is switched off, if
the signal mode is switched between AC and DC and if the device enters standby. The
Max./Min. function can be used together with the relative function.
The Max./Min. function is designed to observe slowly changing signals. A change in the
magnetic field, that is not visible in the display, cannot be captured. The Max./Min. function
should not be confused with a fast Peak function of more sophisticated measuring instruments.
In the following cases the function is particularly useful:
•Measuring very inhomogeneous fields, for example on the surface of magnets. Here
often only the measurement of the maximum value is sufficiently reproducible.
•To capture readings in hard to get at places.
•To display the maximum field when field orientation is unknown. The probe is rotated
slowly and the largest value will be captured.
3.3.11 Limit Menu
If the Limit function is enabled and the measured value is larger than the upper limit level, High
will be displayed. If the measured value is smaller than the lower limit level, Low is displayed
(see Fig. 3). If the measured value is in between, OK is shown.