Combinova MFM 10 User Manual

MFM 10 OPERATOR'S MANUAL

MAGNETIC FIELD

METER 10

Operator’s Manual

The MFM 10 is a professional instrument to measure extremely low
frequency (ELF) magnetic fields.

To make the best use of this instrument, we recommend that you read
this manual carefully.

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CONTENTS

Section 1 - INTRODUCTION

1.1 Magnetic Fields in the Environment

1.2 The Instrument (Fig. 1.1)

1.3 Using the MFM 10

1.4 Combinova AB - The Company Behind the Product

Section 2 - UNPACKING AND INSPECTION

2.1 Unpacking

2.2 Inspection

2.3 Checking the Battery Voltage

Section 3 - OPERATING INSTRUCTIONS

3.1 General Operatlon

3.2 Measurement

3.3 Data Retrieve

3.4 Print

3.5 Check Mode

3.6 Parameters

3.7 Battery Charging

Section 4 - TECHNICAL DESCRIPTION

4.1 Antenna

4.2 Electronics

4.3 Measurement Principle

4.4 Printing with the MFM 10

4.5 Fiber Optic Remote Operation

4.6 Fiber Adapter 10

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CONTENTS

Section 5 - SPECIFICATIONS
Section 6 - ERROR CODES

6.1 Instrument Errors

6.2 Measurement Errors

6.3 Data Retrieve Errors

6.4 Print Errors

WARRANTY FORM

MFM 10 OPERATOR'S MANUAL

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CONTENTS

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Section 1
INTRODUCTION

1.1 Magnetic Fields in the Environment 1.2

1.2 The Instrument 1.3

Page

1.3 Using the MFM10 1.5

1.4 Combinova AB - Behind the Product 1.6

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1 . 1 INTRODUCTION

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The Magnetic Field Meter 10 (MFM 10) is a professional instrument designed to measure
extremely low frequency magnetic fields. The MFM 10 has been developed for self-con­tained field operation with such features as built-in rechargeable batteries, LCD display
and large data logging memory.

MFM 10 has been especially designed for measurement of ELF magnetic fields, emitted
by VDU’s according to MPR 1990:8 “Test methods for Visual Display Units”.

1.1 Magnetic Fields in the Environment

Increasing use of electrical equipment has meant that there is increased exposure to low
frequency magnetic fields. In recent years this has led to concern that a health hazard
could arise from these low frequency magnetic fields. A number of medical and environ­mental studies have indicated that there may be a relationship between magnetic field ex­posure and the frequency of leukemia occurring where there is exposure to field levels of
only 0.2 to 0.3µT.

Strong magnetic fields can also cause electrical interference problems, for example distur­bance of video monitors from external power frequency magnetic fields. The largest mag­netic fields are found around power transmission lines and power supply installations.
Electrical equipment in the home and working environments i.e. photo-copying machines
generate comparatively strong magnetic fields.

Magnetic fields from power lines are directly related to the phase current. Seasonal and
daily variations are caused by different power consumption demands. Close to the power
line the magnetic flux can reach a maximum of 10 to 30µT, but decreases to less than 1µT
at distances of 50 to 200 meters.

Magnetic fields in the home and the working environment are caused both by internal and
external sources. Typical external sources are power line and power distribution substa­tions close to buildings, while even water pipes, when carrying unbalanced neutral cur­rents create significant magnetic fields. Internal sources are the variety of electrical
equipment and wiring.

The usual electrical equipment found in the home or office generate magnetic fields with di­pole characteristics. The field strength decreases rapidly with distance. Close to the
source the field strength can be as high as 10µT, but this decreases to a background level
at only one meter’s distance. In general the background magnetic field should be less than

0.1µT, but in certain cases this could be as great as 1 - 3µT.
The presence of such magnetic fields in the environment is beginning to cause concern,

and has led to demands for action to decrease these fields. This has led to the develop­ment of the MFM 10 which can be easily and quickly used to identify the source of mag­netic fields so that the appropriate action can be taken.

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1.2 The Instrument (Fig. 1.1)

The MFM 10 is a compact, reliable and environmentally protected instrument to measure
low frequency magnetic fields. When detecting and measuring magnetic fields it offers the
following features:

» Orthogonal coils, which means that fields can be measured independent of field di-

rection.

» A frequency range of 10 to 1,000Hz for all low frequency magnetic fields.

» A wide dynamic range of 0.01 to 10,000µT with auto ranging, ensuring that the in-

strument is set at the optimum sensitivity for the detected field.

» True RMS flux measurement, directional component and dominant frequency indica-

tion.

» Polarization detection and presentation.

For the operator in the field the designed portability of the MFM 10 means that the instru­ment is entirely self-contained. These features are:

» Built-in rechargeable sealed lead batteries for portability and additionally avoiding

power supply interference.

» A flexible measurement data logging facility, for up to 100 hours of measurements at

frequent intervals. The stored results can later be printed out or transferred to a PC.

» A complete set of accessories: transport case, tripod, battery charger, communica-

tion cable and this operator’s manual.

» Fiber optic interface kit for communication and remote control.

The electronics in the instrument comprise analog amplifiers, a micro computer with com­munication peripherals and an alphanumerical LCD-display with back light. A built-in clock
and calendar is used in the data logging measurement.

1 . 3 INTRODUCTION

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Fig. 1.1 MFM 10

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MFM 10 OPERATOR'S MANUAL

1.3 Using the MFM 10

The MFM 10 has been designed to be easy to use in the field. A four-key keyboard and
LCD display panel allow the instrument operation to be optimised for the particular meas­urement application. Once the instrument has been set up then measurement is initiated
by simply pressing the start button. The display even informs the operator of remaining
measurement time until the batteries should be recharged.

The main instrument modes are:

» MEASUREMENT

Measurement mode is used to make the actual measurements. A number of differ­ent measurement modes can be selected (single, repetitive and logging).

» DATA RETRIEVE

Data retrieve mode is used to show stored measurement data on the instrument dis­play. Mean period values as well as single measurement data can be accessed in
this mode.

» PRINT

Print mode is used to dump stored data to a printer or computer through the built-in
RS232 serial interface.

» CHECK

Check mode includes a number of tests to verify different instrument functions.

» PARAMETERS

Parameter mode gives the user a wide variety of possibilities to adapt the instrument
for different measurement and communication needs.

Selecting the measurement mode and setting up the MFM 10 is described in Section 3,
Operating Instructions.

A technical description of the MFM 10 is given in Section 4.

1 . 5 INTRODUCTION

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1.4 Combinova AB - Behind the Product

The Magnetic Field Meter 10 has been developed by Combinova AB, who are also respon­sible for the manufacture, marketing and after-sales service of the instrument.

Other field measurement products from Combinova are:

» MFM 1000 - Magnetic Field Meter for the VLF (2-400kHz) range.

» MFM 1020 - Automatic VDT magnetic field measurement system.

» EFM 200 - Electrostatic fields and alternating fields in the ELF (5-2,000Hz) and VLF

(2-400kHz) frequency ranges.

» EFM 100 - Alternating electric fields in the ELF (5-2,000Hz) and VLF (2-400kHz)

frequency ranges.

Combinova AB works with Swedish and international industrial clients in the area of broad
technical development. The principle areas of development expertise are:

- instrument development

- technical trouble shooting

- manufacturing equipment development
This depth of technical experience makes it possible for the company to handle all stages

of product development, including project management and technical co-ordination.

Combinova AB Visiting address:
PO Box 200 50 Fredsforsstigen 22-24
S-161 02 Bromma Bromma, Sweden
SWEDEN

Internet: www.combinova.se
Tel: [phone]

Fax: [phone]

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1 . 7 INTRODUCTION

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Section 2
UNPACKING AND INSPECTION

2.1 Unpacking 2.2

2.2 Inspection 2.3

Page

2.3 Checking the Battery Voltage 2.3

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OPERATOR’S
MANUAL

COMMUNICATION
CABLES

MFM 10

BATTERY
CHARGER

TRANSPORTATION

TRIPOD

Fig. 2.1 Unpacking the MFM 10

CASE

2 . 1 UNPACKING AND INSPECTION

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The MFM 10 is delivered in a specially designed transport box, which also contains all the
accessories that are used with the instrument.

2.1 Unpacking

Inspect the transport case for any damage caused during transit. If damage has occurred,
please contact the shipping company who delivered your instrument.

Open the case and check that the following items have been supplied (see Fig. 2.1) :

Standard Instrument

» MFM 10 instrument

» Battery Charger PS10 (110V or 220V)

» Standard Tripod

» Two Communication Cables (for Printer/Computer)

» Operator’s Manual.

Fiber Optic Remote Control

Included are the following additional items:

» Fiber Interface (internally)

» Fiber Cable (10m) with connectors

» Fiber Adapter 10, for use with an RS232 25-pin PC serial port, is available by sepa-

rate order

If the MFM 10 instrument is to be used for the MFM 1020 Automatic system then it is deliv­ered with a Fiber Optic Remote Control without accessories.

IMPORTANT! Complete the warranty form and return a copy to Combinova AB. The war­ranty is only valid when the warranty form has been completed and received by Combi­nova AB.

Before switching on the instrument, read this manual carefully.

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2.2 Inspection

Inspect the MFM 10 and the accessories supplied for any sign of damage.
Before the MFM10 can be used the voltage of the re-chargeable battery should be

checked. The battery is fully charged when it leaves the factory. However, if for any reason
it has become discharged then the instrument will not operate correctly, and will need to
be recharged.

MFM Checks

- Switch on the instrument, using the ON/OFF button (see Fig. 2.2).
The MFM carries out a number of checks and then displays the following message in the

display panel:

MAGNETIC FIELD MET ER 10s

93.03.08 15:00:00 2

SCROLL SELECT QUIT

ENTER

Battery
charging code

Magnetic Field Meter MFM 10

Note: Refer to Section 3.6 to set the correct time and date!

- Check the battery charging code in the bottom-right of the display panel.
When “0" or ”1" is indicated then the battery should be fully charged. Check the battery

voltage if any of the other codes are shown. To check the battery voltage, see Section

2.3.

2.3 Checking the Battery Voltage

This procedure is fully described in Section 3.5, but a brief guide is given here.

- Switch on the instrument.

- On the control panel select “CHECK” by pressing the “SCROLL” button ( ) four times
so that the display panel shows:

CHECK

93.03.08 15:00:00

- Press the “SELECT” button ( ), and the display panel will show:

CHECK
Battery XX.XV

where XX.XV is the battery voltage.

- Check that the battery voltage is greater than 11.5V. If it is below this voltage then
recharge the instrument (see Section 3.7).

2 . 3 UNPACKING AND INSPECTION

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CONTROL PANEL

ON/OFF SWIT CH

Fig. 2.2 MFM 10

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Section 3
OPERATING INSTRUCTIONS

3.1 General Operation 3.3

3.2 Measurement Mode 3.6

Page

3.3 Data Retrieve 3.8

3.4 Print 3.9

3.5 Check Mode 3.15

3.6 Parameters 3.17

3.7 Battery Charging 3.22

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