Magnaflux 133033 User manual

Operating Manual
FSM-2 Field Strength Measuring Gauge
Part Number 133033

1. APPLICATION
The field strength meter FSM- 2, in conjunction with the tangential field probe,
digitally registers and displays magnetic field strengths (H) in the range of ± 400 A/
cm, enabling you to measure direct magnetic fields as well as alternating magnetic
fields.
Use the FSM-2 for:
• Measuring of the magnetic field strength during magnetisation to check whether
the required field strengths for the magnetic powder test are achieved.
• Measuring the residual field strength on test parts which have already been
inspected.
Magnetic fields of up to Hkomp = 12 A/cm can be compensated for, so that the
sensitive detection of magnetic field variations is also accessible to the meter.
An RS232 output on the bottom of the device enables the transfer of the measure-
ment values to (for example) a computer for subsequent evaluation, analysis and/
or registration.
1.1 SAFETY INFORMATION
The FSM-2 must only be used for measuring tangential magnetic field strengths on
workpiece surfaces.
• DO NOT USE NORMAL BATTERIES for continuous operation when connected
to an external power supply.
• The sensor tip of the tangential field probe must be handled with care. DO NOT -
under any circumstances - use it as a screwdriver or lever; this will lead to the
destruction of the sensor.
• Modifications to the FSM-2 are not permitted.
• Unauthorised use of the FSM-2 will invalidate any guarantees and/or warranties
CONTENTS
1 Application 1
1.1 Safety information 1
2 Identifying parts 2
2.1 Supply 3
2.2 Technical data 3
3 Operation 4
3.1 Switching on 4
3.2 Backlight 4
3.3 Display and operating elements 4
3.4 Tangential field probe 5
3.5 Calibration 6
4 Disposing of the device 6
- EC/EU Declaration of Conformity 6
This operation manual must be kept at the place of work and be accessible to
operators and maintenance personnel at all times.
1

Opening and closing the bottom cover
Hold the device horizontally in one hand, as per the diagram above. With your
other hand, press the cover slightly upwards on the lower edge while, at the same
time, gently pulling the upper edge of the cover away from the device.
Close the cover by gently pressing it shut until the slight closing resistance is over-
come.
Battery compartment
Open the cover for the battery compartment with a screwdriver (NOT with the
probe tip).
NOTE: If the device has been out of service for a long time, replace the battery.
2. IDENTIFYING PARTS
Socket for
connecting
the tangential
field probe
LCD display with selectable backlight
ON/OFF button:
• Turns the unit on and o
• Activates the display background lighting
• Activates the functions selected in the setup
MODE or RMS/PEAK button (depending on the model):
• Selects the operating mode for the device
• Selects the measuring unit
• Calls the Setup Function
ON/OFF button (see below)
MODE or RMS/PEAK button
(see below)
HOLD or RESET button (depending
on the model): stores the displayed
maximum value and implements an
oset compensation for direct fields.
Cover for
closing the
bottom of the
device (see
below)’.
Compartment for
battery pack (9V)
Socket for connecting to power supply
RS232 data
output socket
2

Power supply socket
The FSM-2 meter is suitable for operation with an external power supply (12 V = /
125 mA) in combination with a 9V battery (NiCd or NiMH). The battery is permanently
fed with a small current (maintenance charge).
NOTE: the FSM-2 meter does not automatically switch o when used with the pow-
er supply.
A rechargeable 9V battery can be installed in the unit and will be charged while
the power supply is connected. IMPORTANT: the FSM-2 is NOT equipped with an
overload control so you must:
• adhere to the battery manufacturer´s recommended charging time to prevent the
battery being overcharged;
• Remove the battery block if the device is being used continually with the power
supply.
RS232 data output socket
You can connect the FSM-2 to a PC via the RS232 socket, by using a commercially
available null modem cable. Approximately 10 measurement values per second
can be received via a terminal program and subsequently processed by the user.
All measured values (RMS, positive PEAK, negative PEAK) are transmitted as ASCII
characters, including a number which stands for the set measurement unit.
The transfer protocol is:
• 1 stop bit
• No parity
• 8 bits
• 9600 baud
Data format ASCII:
• +000.0; +000.0; +000.0; 1
• RMS; positive PEAK; negative PEAK
Unit:
1 = A/cm; 2 = kA/m; 3 = mT; 4 = G; 5 = Oe;
This allows you to easily log data as a text download with a terminal program. This
text file can then be analysed using, for example, Microsoft Excel.
2.1 SUPPLY
The FSM-2 field strength meter is supplied with:
• Power supply
• Tangential field probe
• Certificate
• 9V battery pack
• Reference standard 200 A/cm (optional)
• Carry case (optional)
2.2 TECHNICAL DATA
Measuring range ± 400 A/cm
Resolution 0.1 A/cm and/or 0.2 A/cm
(depending on the model)
Eective value for mixed fields
with a peak value of up to: 400 A/cm (True-RMS)
Frequency range 0Hz - 1 kHz (-6 dB)
Warning function
When peak value is exceeded, a clipping
indicator is displayed on the upper right cor-
ner of the display: or or
Measurement value, stop func-
tion Digital trailing pointer
Measurement units available A/cm, kA/m, mT, G, Oe
Battery: 9V-Block Model 6LR61
LCD display, top left-hand side: Indicates current voltage in the battery
LCD display resolution 120 × 32 pixel
Data transfer via RS232 Optional
Operating temperature 0°C to +40°C
Device protection mode IP65 with a closed base cover (splashproof)
Dimensions 168 x 109 x 35 mm
Weight 675 g (FSM-2 with probe and battery)
3

3. OPERATION
3.1 SWITCHING ON
A short press on the ON/OFF key will turn the device on. The operating mode
which was active when the device was last used, will be reactivated. A longer press
of the button will turn the device o.
NOTE: If no measured value is recorded above 12.6 A/cm for about 5 minutes after
switch-on, the device will switch o automatically.
3.2 BACKLIGHT
Once the device is turned on, a short press on the ON/OFF key will activate the
backlight of the LCD display. NOTE: using the backlight will significantly reduce
battery life.
3.3 DISPLAY AND OPERATING ELEMENTS
Setup
Press and hold down the MODE (or RMS/PEAK) and ON/OFF keys together for
approx. 2 seconds. This will take you to the setup menu so you can set the following:
Functions:
• RMS, PEAK, DC
• RMS, PEAK, DC, MAX, MIN
Measurement units: A/cm, kA/m, mT, G, Oe
Press the MODE or RMS/PEAK key to cycle through the settings; select them by
pressing the ON/OFF key. To cancel setup without saving any changes, press
HOLD/RESET key.
NOTE: the LCD display backlight remains activated during setup.
RMS
The RMS function measures the true eective value (True Root Mean Square) of
the magnetic field. The smallest measurable field strength in RMS mode is 2 A/cm;
smaller field strengths will be displayed as ”<2 A/cm“.
NOTE: RMS will often only display the eective value of the alternating field
proportion. The term ‘True RMS’ has been adopted here to dierentiate the
measurements in an arbitrary mixed field.
PEAK
The PEAK function displays the highest values of the positive or negative peak
values for the actual magnetic field without a sign. This allows a quick assessment
of the maximum field strength without considering the polarity.
DC
Displays the DC field proportion of an existing mixed field (the calculated median).
This is an arithmetical median for symmetrical, alternating field parts which are
displayed by a rotary coil instrument.
MAX/MIN
MAX: displays the maximum magnetic field strength value.
MIN: displays the minimum magnetic field strength value.
Magnetic field strength units
• A/cm
• kA/mm [1kA/m = 10 A/cm]
• Oe [1 Oe = 0.796 A/cm]
Magnetic flux density
The FSM-2 field strength meter primarily measures the magnetic tangential field
strength H. It is related to the so-called magnetic flux density Baccording to:
B = μ0• μr• H
Where [μ0 ] is a constant value (magnetic field constant).
The relative permeability [μr ] is dependent on the magnetic flux line of the material
(μr= 1 is valid for a vacuum).
According to the above formula, the FSM-2 will convert the magnetic field strength
Hinto the magnetic flux density Bwhere μr= 1 will be a set value.
The following applies:
• 1 mT = 10 G (Gauss)
• 1 G ~ 0,796 A/cm ~ 1 Oe (Oersted)
4

Operational mode selection
With the FSM-2 in normal operating mode (not in setup mode), press the MODE or
RMS/PEAK button (depending on the model) to cycle through the following display
modes:
• RMS, PEAK, DC
• RMS, PEAK, DC MAX, MIN
The selected operating mode is displayed in the upper left corner of the LCD
display.
HOLD or RESET key (depending on the model)
A short press of the HOLD / RESET button activates the digital trailing-pointer mode.
The function is indicated by the words HOLD / RESET at the top of the display.
Depending on the selected operating mode, a measured value will be displayed
until a new value is measured which exceeds the displayed value. The new value
will then be displayed instead.
This function can be deactivated by pressing the HOLD / RESET button again, or
by pressing the MODE or RMS/PEAK key. (NOTE: the HOLD / RESET key cannot be
activated during DC operating mode).
Oset compensation (tare function)
A zero oset and the oset compensation are only useful for DC fields, although
they must not exceed 12.6 A/cm.
To implement zero compensation, place the probe in a “field-free” location then
press the HOLD / RESET button for approx. 3 seconds. Once the compensation
is successfully completed, the FSM-2 will display a value of approx. 0.0 A/cm and
the symbol 0-> will be displayed in the upper right corner to achieve the activated
tare function.
You can now measure the changes in the magnetic field with regard to the location
where the compensation was performed.
The compensation can be deactivated by pressing on the HOLD / RESET key
again for approx. 3 seconds.
NOTE: the tare function can not be executed in RMS mode due to mathematical
reasons.
3.4 TANGENTIAL FIELD PROBE
The tangential field probe can be permanently connected to the FSM-2 via the
socket on top of the unit.
Hold the probe vertically and place the tip onto the surface being tested, ensuring
that there is no gap between the sensor tip and the surface. The magnetic field
component which comes into contact with the wide side of the sensor tip will be
measured accordingly.
If the probe is rotated by 180° on its longitudinal axis while in DC mode, this will
cause a sign reversal of the displayed value, because the magnetic field vector will
now come into contact with the sensor tip on the other side.
NOTE: the sensor tip must be handled with care. It should never be used as a
screwdriver or lever, as this will cause permanent damage to the sensor.
Positioning the tangential field
probe to measure circular fields
Positioning the tangential field probe
to measure longitudinal fields
1. Probe
2. Direction of magnetic field lines
3. Test part
4. Current flow
1. Probe
2. Test part
3. Magnetic field lines
5

EC/EU DECLARATION OF CONFORMITY
FOR MAGNAFLUX MEASURING INSTRUMENTS
We hereby declare that this equipment complies with the follow-
ing EU standards. The device has been tested and approved. Any
modification made to the device without our written consent will
invalidate this declaration.
Equipment name: FSM-2 Field Strength Meter
Applicable standards:
DIN EN ISO 9934-1:2017-03
DIN EN ISO 9934-3:2015-12
DIN EN 61010-1:2011-07
Authorised person for documentation:
Mr. Georg Koch, Quality Management Ocer
Address:
Magnaflux GmbH, Bahnhofstr. 94-98, D-73457 Essingen, Germany
Person responsible: Signature:
Sales/Design Manager
Mr. Silvio Georgi
Date: 01.01.2017
4. DISPOSING OF THE DEVICE
Before disposing of the FSM-2, check that the power supply is disconnected and
the battery is removed.
Refer to your local waste disposal regulations as chargers, batteries, and button
cells are hazardous waste and pose risks to health and the environment.
Procedure:
• Take the machine out of service.
• Separate the components of the FSM-2 into metals, plastics, composite materials,
electrical components, batteries.
• Dispose of all parts in accordance with local regulations.
If you have any questions, please contact Magnaflux GmbH.
3.5 CALIBRATION
Using long-life robust components reduces the need for daily calibrating. If
required, we can supply a reference standard of 200 A/cm (part number 133042)
as an accessory to help you check the proper functioning of the device.
NOTE: if you order a reference standard once you have started using the FSM-2,
you will need to send the entire unit to Magnaflux GmbH for calibration.
3.5.1 Tangential field probe FSM-2 with reference standard (optional)
The display accuracy of the FSM-2 should be periodically checked using a refer-
ence standard. To do this, lay the probe flat and flush with the groove of the refer-
ence standard, with the white point pointing upwards. There should be a reading
of 200 A/cm ± 4% in the display.
If the displayed value diers by more than 4% from the target value of 200 A/cm,
send the FSM-2, with the probe and reference standard, back to Magnaflux GmbH
for calibration. We recommend that you do this on an annual basis anyway.
3.5.2 Tangential field probe FSM-2 without reference standard
We recommend that the FSM-2 meter, along with its probe, is returned to Magna-
flux GmbH once a year for recalibration.
6

Bahnhofstr 94-98, 73457 Essingen, Deutschland
Telephone: [phone] Fax: [phone]
Email: sales.de@magnaflux.com Web: eu.magnaflux.com/de
Faraday Road, South Dorcan Industrial Estate, Swindon, SN3 5HE, UK
Telephone: + 44 (0)1793 524566 Fax: [phone]
Email: sales.eu@magnaflux.com Web: eu.magnaflux.com