Loma IQ3+ User manual

Document Number: 814195-3.0-ENG
ORIGINAL INSTRUCTIONS
Copyright © 2014 Loma Systems
IQ3+ Metal Detector User Guide

i
Table of Contents
Introduction ..............................................................................................1
About this Guide..................................................................................................................................2
General............................................................................................................................................2
Audience..........................................................................................................................................2
Purpose............................................................................................................................................2
Organisation........................................................................................................................................3
Document Change Control..................................................................................................................4
Document Key.....................................................................................................................................4
Notes and Warnings ........................................................................................................................4
Hyperlinks........................................................................................................................................4
Copyright and Acknowledgements......................................................................................................5
The Loma Group of Companies..........................................................................................................6
About Metal Detection..............................................................................7
How a Metal Detector Works...............................................................................................................8
General............................................................................................................................................8
Balance Stability ..............................................................................................................................8
General and Foil Wrapped Products ...............................................................................................8
Product Effect and Phasing.................................................................................................................8
Product Effect ..................................................................................................................................8
Phasing............................................................................................................................................9
Tracker Feature.................................................................................................................................10
Metal Free Zone................................................................................................................................10
Detector Performance .......................................................................................................................10
Types of Metal...................................................................................................................................12
Shapes and Orientation of Metal.......................................................................................................12
Testing Metal Detector Performance.................................................................................................13
Test Frequency..............................................................................................................................13
Product Test Samples....................................................................................................................14
Test Wands....................................................................................................................................14
Testing Guidelines.........................................................................................................................14
Test Records..................................................................................................................................14
Learn Feature....................................................................................................................................15
Full Learn.......................................................................................................................................15
Update Learn.................................................................................................................................16
Reverse Learn ...............................................................................................................................16
Learn Setup ...................................................................................................................................16

Table of Contents
ii
Safety First.............................................................................................17
Safety Awareness..............................................................................................................................18
EC Declaration of Conformity............................................................................................................18
Safety Warnings................................................................................................................................19
Safety Labels.....................................................................................................................................20
Safety Guards....................................................................................................................................21
Guarding........................................................................................................................................21
Interlock switches...........................................................................................................................21
Safety Relay and Circuits...............................................................................................................21
Responsibilities and Disclaimer.........................................................................................................21
Safety Measures................................................................................................................................22
Intended Use of the Machine ............................................................................................................23
Permitted Use................................................................................................................................23
Improper Use.................................................................................................................................23
Noise Levels......................................................................................................................................23
End of Life Treatment........................................................................................................................23
Emergency Procedures.....................................................................................................................23
Quality Assurance .............................................................................................................................24
ISO9000.........................................................................................................................................24
End User Licence Agreement ...........................................................................................................25
Technical Specifications.........................................................................27
IQ3+ Metal Detector Head.................................................................................................................27
European Belt Conveyors..................................................................................................................28
Installation..............................................................................................29
Installing a Metal Detector Head.......................................................................................................29
Warnings........................................................................................................................................30
Receiving and Unpacking..............................................................................................................30
Moving the Detector Head.............................................................................................................30
Detector Head Mounting Positions................................................................................................32
Mounting a Detector Head onto a Conveyor .................................................................................34
Connecting the Detector Head Electrical Supplies........................................................................38
Installing a Metal Detector System....................................................................................................41
Warnings........................................................................................................................................42
Receiving and Unpacking..............................................................................................................43
Moving the Machine.......................................................................................................................43
Adjusting / Levelling the Conveyor ................................................................................................44
Clearance Requirements...............................................................................................................44
Connecting the Air Supply.............................................................................................................44
Connecting the Electrical Supplies................................................................................................46

Introduction
iii
Checking Belt Tracking (PV belt system only)...............................................................................48
Setting Up Reject Mechanisms......................................................................................................48
Remote User Interface...................................................................................................................48
Installing a Serial Link....................................................................................................................48
Site Considerations ...........................................................................................................................48
Electromagnetic Compatibility (EMC)............................................................................................48
Selection of Frequency Band.........................................................................................................49
Other EMC considerations.............................................................................................................49
Radio Frequency Interference.......................................................................................................49
About the Metal Detector Range............................................................51
Introduction....................................................................................................................................51
Metal Detector Search Heads...........................................................................................................52
Standard Features.........................................................................................................................52
Optional Features ..........................................................................................................................52
Conveyor Belts..................................................................................................................................53
Flat Belts........................................................................................................................................53
Plastic Modular Belts .....................................................................................................................54
Reject Devices...................................................................................................................................55
Reject Devices...............................................................................................................................55
Stop On Detect ..............................................................................................................................55
Air Blast..........................................................................................................................................56
Pusher............................................................................................................................................56
Plough............................................................................................................................................56
Retracting Band.............................................................................................................................56
Powered Decliner...........................................................................................................................56
Signal Only.....................................................................................................................................56
Reject Bins.....................................................................................................................................57
Electrical Services Box......................................................................................................................57
Guards...............................................................................................................................................57
Air Pressure Switch...........................................................................................................................57
Optional Equipment...........................................................................................................................58
Audible Alarm.................................................................................................................................58
‘Bin Full’ Photo-eye........................................................................................................................58
LED Lamp Stack............................................................................................................................58
Overhead Electrical Services.........................................................................................................59
Product Guides..............................................................................................................................59
Product Registration Photo-eye.....................................................................................................59
PVS Indicator Lamp.......................................................................................................................59
Reject Actuation Confirmation.......................................................................................................59

Table of Contents
iv
Reject Confirmation with Photo-eye ..............................................................................................59
Lockable Reject Bin and Status Monitor........................................................................................59
Pack Check Photo-eye ..................................................................................................................59
Getting Started.......................................................................................61
User Interface....................................................................................................................................61
User Access ......................................................................................................................................62
Logging In and Out............................................................................................................................63
Logging In......................................................................................................................................63
Logging Out ...................................................................................................................................64
Starting and Stopping........................................................................................................................65
Starting the Machine......................................................................................................................65
Stopping the Machine....................................................................................................................65
Emergency Stop ............................................................................................................................66
Starting the Machine after an Emergency Stop.............................................................................66
The User Interface.................................................................................67
General Navigation............................................................................................................................67
Title Bar..........................................................................................................................................67
Blue Banner Bar.............................................................................................................................67
Selection Options...........................................................................................................................68
Entering Data.................................................................................................................................68
Saving Settings..............................................................................................................................69
Screens..............................................................................................................................................69
Main Run........................................................................................................................................71
Select Product to Run....................................................................................................................73
Select Product to Setup.................................................................................................................74
Product Options.............................................................................................................................75
Product Settings.............................................................................................................................76
Batch Reset ...................................................................................................................................80
Threshold.......................................................................................................................................81
Learn Options ................................................................................................................................82
Full Learn.......................................................................................................................................82
Update Learn.................................................................................................................................83
Learn Setup ...................................................................................................................................84
System Faults Log.........................................................................................................................87
Select Access Level.......................................................................................................................90
User Accounts................................................................................................................................91
System Setup.................................................................................................................................92
System Settings.............................................................................................................................93
Screen Contents............................................................................................................................93

Introduction
v
Select Access Level.......................................................................................................................95
User Accounts Setup.....................................................................................................................96
User Account Details .....................................................................................................................97
Display ...........................................................................................................................................98
Calendar ........................................................................................................................................99
Appearance Settings......................................................................................................................99
Resultant......................................................................................................................................102
Language Setup...........................................................................................................................103
Calibrate.......................................................................................................................................104
Clean Screen...............................................................................................................................105
Report Options.............................................................................................................................105
User Options................................................................................................................................108
PVS Setup ...................................................................................................................................109
Software.......................................................................................................................................113
Remote Support...........................................................................................................................113
Advanced Settings.......................................................................................................................114
Auto-Learn Settings.....................................................................................................................115
LomaEnet Capture.......................................................................................................................118
LomaOPC Server.........................................................................................................................120
Serial Comms Setup....................................................................................................................121
Diagnostics ..................................................................................................................................123
PQ Analysis .................................................................................................................................124
Coil Current..................................................................................................................................125
Balance........................................................................................................................................126
EnviroScan...................................................................................................................................128
Product.........................................................................................................................................132
Purpose........................................................................................................................................132
Service.........................................................................................................................................137
Engineer / Loma Service..............................................................................................................138
Search Head Setup......................................................................................................................139
Conveyor Setup...........................................................................................................................142
Service Options............................................................................................................................145
GP I/O..........................................................................................................................................147
VF Balance ..................................................................................................................................150
VF Drive.......................................................................................................................................152
Select Product to Setup...............................................................................................................154
Product Options...........................................................................................................................155
Product Settings...........................................................................................................................156
Conveyor Setup...........................................................................................................................160
Rejects Setup...............................................................................................................................163

Table of Contents
vi
Help Manual.................................................................................................................................168
Using the Metal Detector......................................................................169
Good Practice..................................................................................................................................169
Establishing a Good Product Learn.................................................................................................169
Establishing Detector Performance.................................................................................................170
Relative Detectability of Non-Ferrous Metals ..............................................................................170
Regular In-Line Detector Performance Testing...............................................................................171
Handling Rejected Products............................................................................................................171
Getting the Results..........................................................................................................................171
Frequency Selection........................................................................................................................172
Operating Instructions..........................................................................173
Setting Up the Metal Detector.........................................................................................................173
Setting the Time and Date...........................................................................................................174
Setting the Language...................................................................................................................175
Setting the Machine ID.................................................................................................................177
Setting User Access Levels and Passwords ...............................................................................179
Configuring the Metal Detector........................................................................................................180
Setting Up the Search Head........................................................................................................181
Setting Up the Conveyor..............................................................................................................182
Setting Up the Service Options....................................................................................................183
Setting Up the Monitoring Services .............................................................................................185
Setting the VF Balance................................................................................................................186
Setting the VF Drive.....................................................................................................................188
Setting Up the User Options........................................................................................................189
Setting Up Serial Links.................................................................................................................190
Performing a Ferrite Tune............................................................................................................192
Setting Up Product Signal Tracking.............................................................................................195
Adding a New Product.....................................................................................................................200
Learning Products ...........................................................................................................................201
Learning a Product.......................................................................................................................202
Reverse Learn .............................................................................................................................204
Using Performance Validation.........................................................................................................205
Performance Validation System ..................................................................................................205
Enabling the PVS Feature...........................................................................................................206
Enabling PV Testing for a Product...............................................................................................207
Logs and Reports.................................................................................209
Run Errors Log................................................................................................................................210
Purpose........................................................................................................................................210
Screen Contents..........................................................................................................................211

Introduction
vii
Example Problems.......................................................................................................................211
System Faults Log...........................................................................................................................212
Purpose........................................................................................................................................212
Screen Contents..........................................................................................................................212
Example Problems.......................................................................................................................213
Contaminants Log ...........................................................................................................................215
Purpose........................................................................................................................................215
Screen Contents..........................................................................................................................216
Batch Log ........................................................................................................................................216
Purpose........................................................................................................................................216
Screen Contents..........................................................................................................................216
Configuring a Batch Log ..............................................................................................................217
PVS Log ..........................................................................................................................................218
Purpose........................................................................................................................................218
Screen Contents..........................................................................................................................219
Diagnostics Log...............................................................................................................................219
Purpose........................................................................................................................................219
Screen Contents..........................................................................................................................220
Example Messages......................................................................................................................220
Setup Report ...................................................................................................................................221
Purpose........................................................................................................................................221
Screen Contents..........................................................................................................................221
Learn Report....................................................................................................................................222
Purpose........................................................................................................................................222
Screen Contents..........................................................................................................................222
Status Report...................................................................................................................................222
Purpose........................................................................................................................................222
Screen Contents..........................................................................................................................223
Access Log......................................................................................................................................223
Purpose........................................................................................................................................223
Screen Contents..........................................................................................................................224
Example Actions..........................................................................................................................224
Configuration Report .......................................................................................................................224
Purpose........................................................................................................................................224
Screen Contents..........................................................................................................................225
Release Notes.................................................................................................................................226
Purpose........................................................................................................................................226
Log and Report Output Options ......................................................................................................227
Report Languages .......................................................................................................................228

Table of Contents
viii
Maintenance ........................................................................................229
Maintenance Warnings....................................................................................................................229
Cleaning ..........................................................................................................................................229
Cleaning regime...........................................................................................................................229
Cleaning solutions........................................................................................................................230
Belt conveyor versions.................................................................................................................230
Air Regulator Unit Maintenance ......................................................................................................231
Conveyor Belt Maintenance ............................................................................................................231
Plastic Modular Belt Section Replacement..................................................................................231
Setting the Belt Tension and Tracking.........................................................................................231
Adjusting the Drive Chain Tension ..............................................................................................232
Adjusting the Reject Devices...........................................................................................................232
Pusher and Retracting Band Rejects...........................................................................................232
Air Blast Reject ............................................................................................................................232
Software Upgrades..........................................................................................................................232
Glossary...............................................................................................235
Index....................................................................................................239

1
Introduction
Inspection systems are widely used and integrated into production lines within a vast range of
businesses, including the pharmaceutical, food and beverage industries, to identify metal
contamination in products so that they may be removed from the production line and are not supplied
to customers.
Loma Systems has been designing and manufacturing metal detection equipment for over 45 years
and has earned a reputation for consistent quality and advanced technology.
The following sections provide more information:
■About this Guide
This section provides you with a general introduction to the guide, its purpose and the intended
audience.
■Organisation
The guide is organised into a number of chapters providing information in a logical sequence.
This section lists and briefly describes the contents of each chapter.
■Document Change Control
This guide is a controlled document which is subject to change in line with changes to our
products. As the principle aim of the guide is to provide you with the information that you need,
we would welcome any comments or feedback that will enable us to make improvements to the
guide. Please email us at [email protected].
■Document Key
Special text is used throughout the document, highlighted through the use of icons, to add notes
and warnings where appropriate.
■Copyright and Acknowledgements
This guide is copyright to Loma Systems. No part of this document may be reproduced,
transmitted, transcribed, stored in a retrieval system, or translated into any language, or
computer language in any form or by any means without the prior written permission of Loma
Systems.
■The Loma Group of Companies
Loma has offices around the world that can provide you with sales and support services. This
section includes address and contact details for the main offices but details for all offices are
available via the website at www.loma.com.

Introduction
2
About this Guide
General
This guide explains in plain language and by example how to use the IQ3+ Metal Detector Head and
Conveyor. It begins with a conceptual overview of metal detection and then walks through the
processes required to install, operate and maintain the machine. Each process is cross referenced to
detailed information covering the concepts, controls, parts, assemblies, software and items
associated with the process.
Audience
This guide is designed for anyone using the IQ3+ Metal Detector. There are four levels of user access
to the available features and functionality available, each of which provides specific benefits to that
user.
■Operator
The guide benefits operators who need to use the machine functionality and features to carry
out routine product inspections and remove any contaminated products from the production
line.
■Supervisor
The guide benefits supervisors who need to use the machine functionality and features to
manage the selection and inspection of a range of products.
■Quality
This guide benefits quality staff who monitor and analyse inspection data to ensure that
acceptable quality standards are achieved and maintained for all products inspected to meet
customer and legislative requirements.
■Engineer
This guide benefits engineers and technicians who need to initially install, commission and
integrate the machine into the production line and then carry out routine servicing and
maintenance tasks to assure the high availability and performance of the machine.
Even if you are not involved directly in using the IQ3+ Metal Detector, this guide provides you with
general information for using metal detection to prevent products containing contaminants from being
shipped to customers.
Purpose
This guide has two integrated goals:
■Immediate Success
The primary goal is to show users at all levels how to carry out operations and tasks that will
ensure the effective, safe and continued operation of the machine to detect metal contaminants
in products and remove them from the production line.
■Continuing Success
The secondary goal is to provide metal detection guidelines that can be used when setting up
the machine to reliably carry out inspection of specific products.
This guide provides technical and operational information that you can integrate into your in-house
documentation, particularly to meet the requirements of legislation and other standards.

Introduction
3
Organisation
This guide is organised into the following chapters:
■Introduction
Guidelines provide an introduction to this guide and some general information, including global
contact details for Loma Systems.
■About Metal Detection
Guidelines provide an introduction to metal detection, including an explanation of the basic
principles and good practice guidelines.
■Safety First
Guidelines identify explain the safety features built into the machine, potential hazards,
warnings labelling and other general and legislative information related to the safe use of the
machine
■Technical Specifications
Guidelines provide technical information for the machine to generally assist in the site selection
and safe installation processes
■Installation
Guidelines explain how to safely install the machine, including the connection of electrical and
pneumatic supplies
■About the Metal Detector Range
Guidelines provide a summary of the available features and functions of the machine and
descriptions of its component parts.
■Getting Started
Guidelines describe the basic controls and how to switch on, log in and prepare the machine for
use.
■The User Interface
Guidelines describe how to navigate around the user interface and also provide descriptions of
the screen through which you can setup and manage all parameters required for inspecting
products and for the general operation of the machine.
■Using the Metal Detector
Guidelines provide information covering good practice, establishing detector sensitivities and
how to get the best results from your machine.
■Operating Instructions
Instructions are provided describing how to carry set up and configure the machine, including
adding new products for inspection and carrying out performance validation testing.
■Logs and Reports
Guidelines identify the types of logs and reports that are available and describe how to output
them for analysis.

Introduction
4
■Maintenance
Guidelines provide information covering maintenance of the machine to ensure it continues to
operate efficiently and safely.
Each chapter is organised in a logical operational sequence and includes cross-references where
applicable to related guidelines.
Document Change Control
The information contained in this guide is believed to be accurate at the time of writing but may of
course be subject to changes and additions over time to improve on the information provided and in
line with any changes made to the system and its software.
Users are actively encouraged to suggest changes or additions to the contents of this guide directly to
Loma Systems by sending an email to manual[email protected].
All document changes are processed in accordance with the standard Loma Systems document
management system change process.
Document Key
The following special text may be used throughout the document. The icons and colour coding have
the following meanings:
Notes and Warnings
NOTE - Notes as used to provide supplementary information.
WARNING - Warnings are used to identify p
ossible hazards which may cause damage to, or
malfunction of the equipment, loss of life, bodily damage or ill health in any form, either
immediate or latent. Loma Systems cannot be held responsible for injury to anyone,
however caused, where Warnings have been ignored or taken lightly.
Hyperlinks
Main Run Screen Indicates a hyperlink, so tapping on the text will display another page.
[email protected] Indicates an email hyperlink, so tapping on the text will open a new massage
window in your email system.
http://www.loma.com Indicates a web hyperlink, so tapping on the text will open the page in your
default web browser.

Introduction
5
Copyright and Acknowledgements
Copyright © 2014 Loma Systems, a division of ITW Ltd. All rights reserved.
Loma Systems
Summit Avenue
Southwood
Farnborough
Hampshire
GU14 ONY
England
Email: [email protected]
Web: http://www.loma.com
This document is copyright material. No part of this document may be reproduced, transmitted,
transcribed, stored in a retrieval system, or translated into any language, or computer language in any
form or by any means without the prior written permission of Loma Systems.
The information in this guide is believed to be correct at the date of publication. However, our policy is
one of continuous improvement and so the information in this guide is subject to change without
notice, and does not represent a commitment on the part of Loma Systems.
No liability is accepted for errors and omissions in this document. If users are uncertain about
any aspect of the installation of the equipment they should contact an authorised service
centre. Details of these are provided in the Loma Group of Companies section or can be
obtained from www.loma.com.

Introduction
6
The Loma Group of Companies
UK
Canada
Sales Customer and Service Support
Sales and Customer Service
Loma Systems
Southwood
Farnborough
Hampshire
GU14 0NY
United Kingdom
Loma Systems
Unit 11, 333 Wyecroft Road
Ontario
L6K 2H2
Canada
Tel: [phone]
Fax: [phone]
E-mail: [e-mail]
Web: http://www.loma.com
Tel: [phone]
Fax: [phone]
E-mail: [e-mail]
Web: http://www.loma.com
USA and South America
Czech Republic
Sales and Customer Service
Sales and Customer Service
Loma Systems
550 Kehoe Boulevard
Carol Stream
Illinois 60188
USA
Loma Systems
U Lomy 1069
334 41
Dobrany
Czech Republic
Tel: [phone] / 1-800-USA-Loma
Fax: [phone]
E-mail: [e-mail]
Web: http://www.loma.com
Tel: [phone]
Fax: [phone]
E-mail: [email protected] / [email protected]
Web: http://www.loma.com
China
Benelux
Sales and Customer Service
Sales and Customer Service
Loma Systems Shanghai (Asia HQ)
Shanghai
Loma Systems
Door 3, No. 15, Lane 1985
Chunsen Road, Shanghai, 200237 PRC
Loma Systems / Lock Inspection
Daalderweg 17
4879 AX Etten-Leur
Netherlands
Tel: [phone]
Fax: [phone]
E-mail: [e-mail] /
[email protected]
Web: http://www.loma.com
Tel: [phone]
Fax: [phone]
E-mail: [e-mail] / bnl.servic[email protected]
Web: http://www.loma.com
France
Germany
Sales and Customer Service
Sales and Customer Service
Lock Inspection France
120, rue Jean Jaurès
92300 Levallois-Perret
France
Loma Systems
A division of ITW Test & Measurement GmbH
Magnusstr. 18
D-46535 Dinslaken
Deutschland
Tel: [phone]
Fax: [phone]
E-mail: [e-mail] /
[email protected]
Web: http://www.loma.com
Tel: [phone]
Fax: [phone]
E-mail: [e-mail] / [e-mail]
Web: http://www.loma.com
Poland
Brazil
Sales and Customer Service
Sales and Customer Service
Loma Systems
Wiśniowy Business Park
ul. Iłżecka 26, Budynek E
02-135 Warszawa
Poland
Loma Systems / Brapenta Electronica
Baráo do Rio Branco
753 – Santo Amaro
São Paulo, SP – Brasil
CEP 04753-001
Tel: [phone]
Fax: [phone]
E-mail: [e-mail]
Web: http://www.loma.com
Tel: [phone]
Fax: [phone]
E-mail: [e-mail]
Web: http://www.loma.com / www.brapenta.com
For details of other Loma offices and the worldwide distributor network, please visit www.loma.com.

7
About Metal Detection
Industrial metal detectors are used in the pharmaceutical, food, beverage, textile, garment, plastics,
chemicals, lumber, and packaging industries.
Contamination of food by metal shards introduced during the manufacturing process is a major safety
issue in the food industry. Metal detectors are widely used and integrated into production lines and
play a vital role in preventing contaminated products from reaching customers.
The following sections contained in this chapter provide a conceptual overview to explain what metal
detection is, the reasons for metal detection, how metal detection works and how to implement metal
detection successfully:
■How a Metal Detector Works
All metals are magnetically conductive, electrically conductive or both. When they enter an
electromagnetic field they create a detectable disturbance, or signal, in the field and this is used
to detect the presence of metal contaminants in food and pharmaceutical products.
■Product Effect and Phasing
Explains what product effect is and how phasing is used to reduce its impact on detecting
contaminants.
■Tracker Feature
The Tracker feature when enabled, continuously adjusts the product signal threshold
automatically, using the average signal values obtained from a defined number of products that
pass through the aperture.
■Metal Free Zone
Although the electromagnetic field is generated inside of the detector housing, some of the field
emanates out of the aperture on both sides. This ‘leakage’ area is defined as the Metal Free
Zone.
■Detector Performance
Provides details of factors that affect the performance of a metal detector and gives typical
levels of detection performance for different product types.
■Types of Metal
Provides details of the types of metal that typically be detected and the ease of detection,
dependant on their physical characteristics
■Shapes and Orientation of Metal
Provides information covering how the shape of a metal contaminant and its orientation when
passing through the metal detector aperture can affect its detection.
■Testing Metal Detector Performance
Regardless of how sophisticated and reliable a metal detector is, it is only as good as the
frequency and thoroughness of the testing programs supporting it. This section provides
guidance for testing your metal detector performance.
■Learn Feature
The Learn feature incorporated into the metal detector completely automates the configuration
of the detector settings for a product. The Learn process options available are described in this
section.

About Metal Detection
8
How a Metal Detector Works
General
All metals are magnetically conductive, electrically conductive or both. When they enter an
electromagnetic field they create a detectable disturbance, or signal, in the field.
Modern metal detectors allow this signal to be detected, providing the opportunity to operate a reject
device to remove the contaminated product from the production line.
The head houses a transmitter coil that broadcasts a low to medium radio frequency (RF) signal
which generates the electromagnetic field. Two receiver coils are also located in the head on either
side of the transmitter coil.
The receiver coils pick up any disturbance as caused by a metal contaminant. This is then digitally
processed to generate a resultant signal. If the signal exceeds the performance threshold set for the
product being inspected then detection is triggered, providing an opportunity to remove the
contaminated product from the production line.
Balance Stability
Very small movements of the metal detector, caused by temperature changes, vibration from nearby
equipment and other factors, can disturb the balance of the three coils. This can cause the metal
detector to falsely indicate the presence of metal; commonly called ‘false triggering’.
The robust construction and excellence in electronics and software design of Loma metal detectors
provides a stable and reliable product where the likelihood of false triggering is minimised.
General and Foil Wrapped Products
Modern metal detectors fall into two main categories. The first category consists of systems with a
general purpose search head. These systems are capable of detecting ferrous and non-ferrous
metals as well as stainless steels, in fresh and frozen products; either unwrapped or wrapped and
even in metallized films.
The second main category consists of systems which have a ferrous-in foil search head that uses a
series of magnets rather than a balanced coil. These systems are capable of detecting ferrous metals
within fresh or frozen products which are packed in foil wrapping.
Product Effect and Phasing
Product Effect
Not only are all metals magnetically conductive, electrically conductive or both, but also the products
being inspected can also have one or both of these characteristics. In effect, when a contaminated
product is passed through the aperture, the metal detector sees a single resultant signal consisting of
both the product signal and the metal contaminant signal.
For example, iron enriched products such as cereals create a large magnetic signal that hampers the
detectors ability to detect the magnetic signal of small pieces of metal. These are commonly called
‘Dry’ products which typically include meat, cheese, bread, fish, dairy products and salad items.
Conversely, products with high moisture and salt content such as bread, meat and cheeses, are
electrically conductive, again hampering the metal detectors ability to detect small pieces of metal.
These are commonly called ‘Wet’ products which typically include cereal, crackers, flour, powders,
frozen food products and peanut butter.
For the metal detector to identify that the product contains a metal contaminant and trigger detection,
the signal from the contaminant must therefore be greater than the product signal.

Safety First
9
Phasing
The diagram below shows how the magnetic and conductive properties of a product affect the product
phase angle.
Utilising the ‘Learn’ feature provided in the IQ3+ Metal Detector, an average for the net signal received
from a product during inspection is digitally processed to provide a phase angle and amplitude.
This is then memorised for later recall against the product as a product ‘window’, as shown in the
Product Signal diagram below and essentially provides a ‘filter’ so that signals of a known phase and
amplitude can be ignored. This is called ‘phasing out’ the product signal.
Product Signal
Contaminated Product Signal
The Contaminated Product Signal diagram above shows how a signal from a metal contaminant,
although much smaller than the product signal, can be easily detected.
The metal detector sees the one resultant signal of the metal contaminant and product signals
presented together at the same time.
This resultant signal still falls well outside of the product ‘window’ which then triggers detection and
provides an opportunity for the contaminated product to be rejected from the production line.

About Metal Detection
10
Tracker Feature
As well as capturing and memorising the product ‘window’ during a ‘Learn’ process, the IQ3+ Metal
Detector also includes a Tracker feature which when enabled continuously adjusts the product
‘window automatically, using the average signal values obtained from a defined number of products
that pass through the aperture. This allows the detector to compensate for slight changes in the
phase angle and amplitude of the product signal.
For example, for a frozen product the product effect is very small when the product has just come out
of the freezer. This allows a low working threshold level to be used giving a high sensitivity to metal
contaminants. However, if the line stops for any reason then the product could thaw slightly, or if the
product were not fully frozen, a significant product signal increase may result. In this event the
working threshold will have to be raised to allow the product to be passed, without false rejection.
Raising the working threshold to allow thawed product to pass without false rejection may reduce the
sensitivity to metal contamination. If the product becomes hard frozen the working threshold may be
higher than it now needs to be, so the sensitivity to metal contamination will not be as good as it could
be.
Tracking works by recording the product signal for each pack. From the values read, the working
threshold continuously trends upward or downward between an upper and a lower limit. The rate and
amount by which the working threshold changes together with limits between which it operates are
controlled by user entered parameters for each product.
It should be noted that this type of system may allow metal contamination that would otherwise be
detected if changes in the product force the working threshold to rise sharply.
Tracker initialisation will occur whenever the detector is powered on, the running product is changed
or the tracking limit parameters are changed. Upon completion of the product learn routine the derived
working threshold will be used unless the product signal initiates a change.
Metal Free Zone
Although the electromagnetic field is generated inside of the detector housing, some of the field
emanates out of the aperture on both sides. This ‘leakage’ area is defined as the Metal Free Zone,
meaning an area external to the metal detector aperture which must be free of any fixed or moving
metal as it generates a signal that will be picked up by the metal detector and added to the signal
being produced by the product and any contaminant. This could result in false triggering and rejection
of good products.
Loma Systems generally employ the use of fixed plastic guards fitted around both ends of the
aperture. This serves a dual purpose in effectively preventing access to those areas and the
accidental introduction of any metal contaminants.
Detector Performance
For optimum detector performance, the search head must be of an appropriate size for the specified
product. Smaller apertures generally allow smaller pieces of metal to be detected; the exception being
products packaged in metallised film and highly conductive products such as large blocks of cheese.
In production, detector performance is affected by the following:
■Size of detector aperture
■Detector type
■Head operating frequency
■Product temperature
■Conveyor speed
■Environmental conditions
■Product presentation