GMW BARTINGTON MAG-03 User manual

GMW
_________________________________________________________________________________
GMW
955 Industrial Road, San Carlos, CA 94070 Tel: [phone] Fax: [phone]
Email: [email protected] Web site: http://www.gmw.com
BARTINGTON
MAG-03
THREE AXIS MAGNETIC FIELD SENSORS
OPERATION MANUAL
Distributed by:
GMW Associates
955 Industrial Road, San Carlos, CA 94070
Tel: [phone] Fax: [phone]
Email: [email protected] Web Site: http://www.gmw.com
Manufactured by:
Bartington Instruments Ltd.
10 Thorney Leys Business Park
Witney, Oxford OX8 7GE
England
Tel: [phone] Fax: [phone]
Email: [email protected] Web Site: http://www.bartington.com/ Issue 20 May 2005

OM1004 ISSUE 20 PAGE 1 OF 30
OM 1004
OPERATION MANUAL FOR
Mag-03 RANGE OF THREE AXIS
MAGNETIC FIELD SENSORS
Bartington Instruments Ltd
10 Thorney Leys Business Park
Witney
Oxford
OX28 4GG
England
Telephone [phone]
Facsimile [phone]
E-mail [email protected]
Internet http://www.bartington.com/
Bartington Instruments reserves the right to change any part of the design of these products
without prior notice.
These products are not qualified for use in explosive atmospheres or life support systems.
Consult Bartington Instruments for advice.
The copyright of this document is the property of Bartington Instruments Ltd. The document
is supplied on the condition that it is to be treated commercially confidential and it may not
therefore be disclosed to any third party without the prior written authorisation of the
Managing Directors of Bartington Instruments.

OM1004 ISSUE 20 PAGE 2 OF 30
LIST OF CONTENTS
1 INTRODUCTION
2 GENERAL DESCRIPTION
3ENCLOSURES
3.1 Mag-03MC
3.2 Mag-03MCES
3.3 Mag-03MCFL
3.4 Mag-03MS
3.5 Mag-03MSES
3.6 Mag-03MSS
3.7 Mag-03IE
3.8 Mag-03IE Version 2
3.9 Mag-03MCTP
3.10 Mag-03MCUP
4 ACCESSORIES
4.1 Mag-03PSU POWER SUPPLY UNIT
4.2 Mag-03DAM DATA ACQUISITION MODULE
4.3 Mag-03SCU SIGNAL CONDITIONING UNIT
4.4 Mag-03MC-CU CALIBRATION UNIT
4.5 Mag-03MS-CU CALIBRATION UNIT
4.6 CABLES
4.7 Mag-03MC-BR MOUNTING BRACKET
4.8 MATING CONNECTORS
5 MOUNTING
5.1 Mag-03MC/Mag-03IE
5.2 Mag-03MS
5.3 Mag-03MSS
5.4 OTHER TYPES
6OPERATION
6.1 CONNECTOR PIN ALLOCATION
6.2 INTERFACE
6.3 POWER SUPPLIES
6.4 SIGNAL/POWER GROUND
6.5 CABLING
6.6 CONNECTING POWER
6.7 RESPONSE
6.8 ELECTROMAGNETIC COMPATIBILITY
7 PERFORMANCE
7.1 FREQUENCY RESPONSE
7.2 NOISE
7.3 OVER RANGE
8 SIGNAL PROCESSING

OM1004 ISSUE 20 PAGE 3 OF 30
9 CARE AND MAINTENANCE
10 MAGNETIC UNITS AND MEASUREMENTS
10.1 CONVENTIONS
10.2 MEASUREMENT UNITS
10.3 CONVERSION TABLE
10.4 VECTOR MEASUREMENTS
11 TECHNICAL SPECIFICATIONS
11.1 SENSORS
11.2 CABLES
12 FIGURES
13 CALIBRATION CERTIFICATES

OM1004 ISSUE 20 PAGE 4 OF 30
LIST OF FIGURES
FIGURE 1 Mag-03MC SENSOR OUTLINE WITH MATING CONNECTOR
FIGURE 2 Mag-03MCES SENSOR OUTLINE WITH MATING CONNECTOR
FIGURE 3 Mag-03MCFL SENSOR OUTLINE
FIGURE 4 Mag-03MS SENSOR OUTLINE WITH MATING CONNECTOR
FIGURE 5 Mag-03MSES SENSOR OUTLINE WITH MATING CONNECTOR
FIGURE 6 Mag-03MSS SENSOR OUTLINE WITH MATING CONNECTOR
FIGURE 7 Mag-03IE SENSOR OUTLINE WITH MATING CONNECTOR
FIGURE 8 Mag-03IE VERSION2 SENSOR OUTLINE
FIGURE 9 Mag-03MCTP SENSOR OUTLINE WITH MATING CONNECTOR
FIGURE 10 Mag-03MCUP SENSOR OUTLINE
FIGURE 11 Mag-03MC CABLE
FIGURE 12 Mag-03MCES CABLE
FIGURE 13 Mag-03MS CABLE
FIGURE 14 Mag-03MSES CABLE
FIGURE 15 Mag-03MSS CABLE
FIGURE 16 Mag-03MC-BR MOUNTING BRACKET
FIGURE 17 Mag-03 INTERFACE SCHEMATIC
FIGURE 18 Mag-03 TYPICAL AMPLITUDE & PHASE RESPONSE
FIGURE 19 Mag-03 NOISE PLOT STANDARD VERSION
FIGURE 20 Mag-03 NOISE PLOT LOW NOISE VERSION

OM1004 ISSUE 20 PAGE 5 OF 30
1 INTRODUCTION
This manual describes the operation of the Mag-03 range of three axis magnetic field sensors.
These compact high performance sensors with integral electronics provide measurements of
static and alternating magnetic fields in three axes. The sensors, alternatively described as
magnetometers, convert magnetic flux density, measured in three axes, into a bipolar analog
voltage. Analog output voltages Vx, Vy and Vz are in linear proportion to the flux density.
In designing the Mag-03 series, the policy has been to provide a high performance sensor
having a flat amplitude response and a small, predictable phase lag over a wide bandwidth.
In order to offer maximum flexibility and not degrade the performance, the sensor has no
internal filters. The analog outputs may require external filters to optimise the performance
depending on the application. The Mag-03PSU power supply contains simple filters which
may be sufficient, but for more stringent requirements the Mag-03SCU signal conditioning
unit may be appropriate.
The sensors are available in a variety of enclosures, as detailed below, with five measuring
ranges. A low noise version can be supplied in all packages with a measuring range of
±70μT or ±100μT.
TYPE ENCLOSURE MEASURING RANGE (μT) ORTHOGONALITY
ERROR (°)
70 100 250 500 1000 0.1 0.5
Mag-03MC Cylindrical ***** *
Mag-03MCES Cylindrical - environmentally
sealed connector ***** *
Mag-03MCFL Cylindrical with flying leads ***** *
Mag-03MS Square section ***** *
Mag-03MSES Square section -
environmentally sealed
connector
***** *
Mag-03MSS Square section submersible to
100 metres ***** *
Mag-03IE Cylindrical with independent
elements *****
Mag-03MCTP
(to special order) Cylindrical - two part construction ***** *
Mag-03MCUP
(to special order) Unpackaged ***** *
TABLE 1. Mag-03 SENSORS
Products are specified as Mag-03 followed by the enclosure code (MC, MCES, MCFL, MS,
MSES, MSS or IE) followed by L for the low noise version only, then the measuring range
(70, 100, 250, 500 or 1000μT).
e.g. Mag-03MSL70 is a square section low noise sensor with a range of ±70μT
Mag-03MC1000 has a cylindrical enclosure and a range of ±1000μT
A re-calibration service is available which is traceable to international standards.

OM1004 ISSUE 20 PAGE 6 OF 30
2 GENERAL DESCRIPTION
This section describes the features common to the Mag-03 range of sensors. Where there are
exceptions they are described under Section 3 detailing the different types of enclosures.
Three fluxgate sensing elements are mounted orthogonally at one end of an enclosure which
also contains the electronic circuitry. The connector is mounted at the opposite end of the
enclosure. The position and direction of each sensing element is shown on the outside of the
sensor, together with the product code, measuring range and serial number.
Details of the enclosures, mounting, connector dimensions, connector pin allocation and the
position of the sensing elements relative to the enclosure are given on the relevant figure
showing the outline and connector detail. The sensor elements are precisely aligned along
the centre lines of the package.
The sensors require a power supply of between ±12V and ±17V and provide three high
precision analog outputs of 0 to ±10V full scale, proportional to the magnetic field along each
axis. For a unit with a full scale range of ±100μT the output voltage for each axis is 0.1V/μT
of the field in the direction of that axis. The relationship between the magnetic field and the
analog output is extremely linear and the frequency response is maximally flat from d.c. to
1kHz with a bandwidth of 3kHz.
The low output impedance of the sensor ensures it can be operated over long cables and
permits it to be interfaced to low impedance data acquisition systems. The zero field offset
error, scale factor, orthogonality and frequency response are individually calibrated.
3 ENCLOSURES
3.1 Mag-03MC - Figure 1
The sensing elements and electronic circuitry are housed in a reinforced epoxy cylindrical
enclosure with a circular connector. The sensor is suitable for use in shallow boreholes but is
not sealed against the ingress of water. A mounting bracket is available as an option. The
label area is recessed and should not be used for clamping.
3.2 Mag-03MCES - Figure 2
This enclosure is the same as the Mag-03MC but features a rugged, seven way sealed
connector to provide a splash-proof unit.
3.3 Mag-03MCFL - Figure 3
This enclosure is identical to the Mag-03MC except that no connector is used, a seven way
connecting cable is moulded within the enclosure with a strain relief grommet. The standard
length of flying lead is 500mm.

OM1004 ISSUE 20 PAGE 7 OF 30
3.4 Mag-03MS - Figure 4
This square section enclosure is manufactured from reinforced epoxy and the sensing
elements are mounted with reference to the base which acts as a datum face.
The Z axis is aligned to this reference face to an accuracy of 0.1°. The orthogonality error
between the magnetic axes is also 0.1°for this sensor compared to the standard 0.5°error for
the other sensors in the range.
The connector is a nine pin D type plug and has pillars for securing the mating connector.
The pillars are tapped with UNC 4-40 threads, standard for this type of connector, but the use
of retaining screws on the mating connector should be avoided unless it can be ascertained
that they contain no magnetic material, which would influence the field at the sensor
elements. Retaining screws commonly contain spring washers or circlips which are
manufactured from ferrous material which render them unsuitable.
3.5 Mag-03MSES - Figure 5
This enclosure is the same as the Mag-03MS but features an environmentally sealed
connector to provide a splash-proof unit. The connector is a rugged, seven way sealed type.
A sealing gasket may be required on the base of the sensor.
3.6 Mag-03MSS - Figure 6
This square section enclosure is designed for marine use and is submersible to depths of 100
metres. The pressure housing is manufactured from polyacetal for minimum water
absorption.
The connector is a seven way marine type and the mating connector is supplied moulded to a
seven way polyurethane jacketed marine cable. The cable is supplied to customer
requirement up to a length of 600 metres.
3.7 Mag-03IE - Figure 7
This sensor has a shortened cylindrical enclosure for the electronics and the three sensing
elements are individually potted and connected to the electronics assembly with flying leads
which have a standard length of 750mm. This allows the user to position the individual
elements independently if required. The sensing elements can be arranged around a sensitive
volume where space is restricted. The connector is the same as for the Mag-03MC.
3.8 Mag-03IE VERSION 2 - Figure 8
This sensor is identical to the Mag-03IE except that Version 2 has a 5m cable attached with a
25 pin ‘D’ type connector. The bandwidth is increased to 5kHz.
3.9 Mag-03MCTP - Figure 9
This enclosure provides a two part construction. The sensing elements and electronics are
contained in two separate cylindrical enclosures connected by a 1000mm ribbon cable and a
simple eight pin dual in-line socket. The sensing elements are completely encapsulated in
epoxy resin within their enclosure. The external connector is the same as for the Mag-03MC.

OM1004 ISSUE 20 PAGE 8 OF 30
3.10 Mag-03MCUP - Figure 10
This arrangement is an “unpackaged” version. The sensing elements are encapsulated in a
cylindrical enclosure but the electronics printed circuit board is simply coated in silicone
rubber and not protected by an enclosure. Two four-way ribbon cables, with a standard
length of 140mm but available in lengths to 500mm, connect the sensing elements to the
electronics board. Connection to the complete unit is by a flying lead.
4 ACCESSORIES
The optional accessories for the Mag-03 range of sensors are as follows:
4.1 Mag-03PSU POWER SUPPLY UNIT
This unit supplies power to any of the Mag-03 sensors from an internal rechargeable battery.
It produces a fully isolated ±12V supply which provides 10 hours of continuous operation.
The battery can be recharged in a few hours using the mains adaptor provided. A high pass
and a low pass filter are provided in each signal path to provide a.c. or d.c. response and to
remove high frequency noise.
Full specifications of the Mag-03PSU are provided in the Mag-03 brochure DS0013 and the
operation manual OM0065.
4.2 Mag-03DAM DATA ACQUISITION MODULE
This is a 24-bit resolution, low speed, six channel data acquisition module which runs under
software control from the user’s PC. Data from one or two triaxial sensors is stored to disk
and may be imported to a suitable spreadsheet for plotting. The module is mains or battery
powered. Full details of the Mag-03DAM are provided in the Mag-03 brochure DS0013 and
in the operation manual OM0658.
4.3 Mag-03SCU SIGNAL CONDITIONING UNIT
This mains powered signal conditioning unit supplies power to a three axis sensor and allows
a filter to be configured with separate controls for the low pass and high pass sections. The
filter is applied to each output channel of the sensor. Control of gain and offset is provided
for each channel independently. Full details are provided in the brochure DS0012 and the
operation manual OM0941.
4.4 Mag-03MC-CU CALIBRATION UNIT
The Mag-03MC-CU is a battery powered unit which produces a sinusoidal alternating
magnetic field of defined frequency and magnitude. It provides a reference magnetic field
for testing the calibration of the Mag-03 sensors which have a cylindrical enclosure. A
temperature stabilised constant current is passed through a single Helmholtz coil with guides
to align each of the sensor axes in turn. Full details are provided in the Mag-03 brochure
DS0013.

OM1004 ISSUE 20 PAGE 9 OF 30
4.5 Mag-03MS-CU CALIBRATION UNIT
The Mag-03MS-CU is a battery powered unit similar to the Mag-03MC-CU above but for
calibration of the Mag-03MS sensors which have a square section. Contact Bartington
Instruments for full details.
4.6 CABLES
Cables are available for connection of the three axis range of sensors to the Mag-03PSU,
Mag-03DAM or Mag-03SCU. Specifications for each of the cables are given in Section 12.
The cables are shown, with their connector pin allocations, in the following figures:
Mag-03MC cable - FIGURE 11 (also used for Mag-03IE)
Mag-03MCES cable - FIGURE 12
Mag-03MS cable - FIGURE 13
Mag-03MSES cable - FIGURE 14
Mag-03MSS cable - FIGURE 15
4.7 Mag-03MC-BR MOUNTING BRACKET (Figure 17)
This mounting bracket for the Mag-03MC cylindrical sensor clamps around the sensor body
and provides mounting holes. The bracket is manufactured from reinforced epoxy resin and
is supplied complete with nylon mounting screws.
4.8 MATING CONNECTORS
All sensors, except for the Mag-03MSS, are supplied with a non-magnetic mating connector
if no cable for connection to a power supply or data acquisition module is purchased.
The Mag-03MSS mating connector must be purchased separately.
5 MOUNTING
The method of mounting will depend on the application and the enclosure. For details of the
mounting arrangements refer to the relevant outline drawing. The use of magnetic materials
in the mounting arrangement must be avoided. All mounting components should be checked
before installation by introducing the component within the immediate vicinity of the sensing
elements of a working magnetometer and observing any variation in the background field.
The analog output is positive for conventional flux direction South to North in the direction
of the arrow shown on the label for each axis. i.e. the maximum positive output will be
obtained from any axis when the arrow points towards magnetic north along the total field
vector.
5.1 Mag-03MC, Mag-03MCES, Mag-03MCFL and Mag-03IE
These sensors may be supported in the Mag-03MC-BR mounting bracket described in
section 4.6. The label area of the sensor is recessed and should not be used for clamping.
5.2 Mag-03MS and Mag-03MSES
These sensors have threaded holes tapped in the base which is also the datum face. The
sensors can be mounted on any flat, non-magnetic surface using the two brass screws