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Metal Detection - The Basics. North America Fortress Technology Inc. Toronto, Canada Phone: (416) 754-2898 Fax: (416) 754-2976 Email: fortress@fortresstechnology.com. Europe Fortress Technology (Europe) Ltd. Banbury, UK Phone: +44 (0) 1295 256266 Fax: +44 (0) 1295 265277
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Metal Detection - The Basics North America Fortress Technology Inc. Toronto, Canada Phone: (416) 754-2898 Fax: (416) 754-2976 Email: fortress@fortresstechnology.com Europe Fortress Technology (Europe) Ltd. Banbury, UK Phone: +44 (0) 1295 256266 Fax: +44 (0) 1295 265277 Email: europe@fortresstechnology.com Fortress Technology Ltd. www.fortresstechnology.com
Contents 1. Metal Detection - The Basic Principles 1.1 Theory of Operation 1.2 Product Effect and Phasing 1.3 Metal Free Area 1.4 Sensitivity 1.5 Types of Metal 1.6 Shapes and Orientation 2. Testing 2.1 Test Sample 2.2 Frequency 2.3 Procedure 2.4 Records 3. Sources of Interference 4. Applications 4.1 Conveyor (End of Line) 4.2 Gravity 4.2 Pipeline 5. Good Practice Guidelines Fortress Technology Ltd. www.fortresstechnology.com
Transmitter Coil Receiver 1 Receiver 2 Balanced Coil Fortress Technology Ltd. www.fortresstechnology.com
Receiver 2 Transmitter Coil Receiver 1 Balanced Coil Fortress Technology Ltd. www.fortresstechnology.com
Conductive Scale Magnetic Scale Product Effect Fortress Technology Ltd. www.fortresstechnology.com
Phasing Resistive (Conductive) R Stainless Steel (1 mm) I.e 304. 316 Non Ferrous (1 mm) I.e. Copper, Brass, Ali. Ferrous (1 mm) I.e. Iron Steel 0 Reactive (Magnetic) x Fortress Technology Ltd. www.fortresstechnology.com
Phasing With Product Resistive (Conductive) R Conductive/ Wet Product (meat, cheese, moist bread) Stainless Steel (1 mm) I.e. 304. 316 Non Ferrous (1 mm) I.e. Copper, Brass, Ali Ferrous (1 mm) I.e. Iron, Steel Reactive (Magnetic) x Fortress Technology Ltd. www.fortresstechnology.com
Total Metal Free Area Metal Free Area Fortress Technology Ltd. www.fortresstechnology.com
Signal Size Metal Size 3 1 2 Aperture Size 1 2 3 Position in Aperture Sensitivity Fortress Technology Ltd. www.fortresstechnology.com
Types of Metal 2.0mm Fe 2.0mm Fe 2.0mm Non Fe 3.0mm Non Fe 4.0mm SS 3.0mm SS Dry Product Mode Wet Product Mode (Example of Ratios ONLY) Fortress Technology Ltd. www.fortresstechnology.com
Travel A B C Shapes & Orientation of Metal • Ferrous Wires: • A - Easiest position, biggest signal. • B, C - Hardest Position, smallest signal. • Non-Ferrous and Stainless Steel Wires: • B, C - Easiest position, biggest signal. • A - Hardest position, smallest signal. Fortress Technology Ltd. www.fortresstechnology.com
Dry Product Ferrous & Non Ferrous Wet Product Ferrous Non Ferrous Aperture Height < 0.8 -1.0 mm < 1.5 mm < 2.0 mm Up to 50 mm (2 In) < 1.0 -1.2 mm < 2.0 mm < 2.5 mm Up to 125 mm (5 In) < 1.2 - 1.5 mm < 2.5 mm < 3.0 mm Up to 200 mm (8 In) Typical Guidelines for Sensitivity Fortress Technology Ltd. www.fortresstechnology.com
5. Metal Free Belt 1. Metal Free Area 6. Roller Isolation 2. Non-Metallic Slider Bed 3. Clearance 4. Foot Isolation Detector Performance • Isolated Rollers - prevent loops • High Quality Belt - Metal Free, Carbon Free, Interlocked finger • Splice, or Plastic Modular Belt (White or Natural) • Low vibration and Static • Adequate metal free area Fortress Technology Ltd. www.fortresstechnology.com
Air Blast Retracting Belt Reject Reject Reject Flap Gate Photo Eye Reject Reject Typical Metal Detector Conveyor Reject Reject Options Diverter Pusher Fortress Technology Ltd. www.fortresstechnology.com
Product Freefall Start Point (Test Piece Access) Drop Height Distance D1 Plastic Pipe Selection Detector D2 Overall Length Detector To Valve Distance Reject Output Good Product Output Drop Through / Gravity Metal Detector Fortress Technology Ltd. www.fortresstechnology.com
Drop Through / Gravity Metal Detector • A drop through / gravity detection system is ideally suited to inspecting dry, free flowing products such as : • Grains, flours, cereals • Rice, nuts, sugar • Plastic pellets and flakes • The following critical factors must be known when designing a • successful drop through / gravity detection system: • Flow rate • Bulk density • Free fall distance • Pipe size • Space available • Testing procedure (insert + recovery) Fortress Technology Ltd. www.fortresstechnology.com
D1 Non Metallic Pipe Section Detector Reject Valve Good Product Flow Rejected Product Pipe System Fortress Technology Ltd. www.fortresstechnology.com
Pipeline Metal Detector • A pipeline inspection system is ideally suited to inspecting liquid, • slurries or paste products that can be pumped through. • Typical pipe products would include: • Sauces • Dairy products • Meat slurries • Juices etc. • The following critical factors must be known when designing a • successful pipeline detection system: • Pipe I.D. • Pipe clamp connection style (tri-clamp, I-line etc) • Product flow rate (GMP) • Product viscosity • Product temperature range • Product pressure • Expected cleanup procedures (wash down, pipe pig, etc.) Fortress Technology Ltd. www.fortresstechnology.com
Metal Detection System Sensitivity Q&A Test Form Location Date & Time Samples Used Results (signals) Corrective Action Fortress Technology Ltd. www.fortresstechnology.com
Good Practice 1. Prevention 1.1 Training 1.2 Controlled Maintenance 1.3 Regular Inspection & Good Housekeeping 2. Sensitivity 2.1 Identify Standards for products (maximise sensitivity) 2.2 Use Security methods (passwords) 3. Testing 3.1 Determine Frequency 3.2 Create Test packs 3.3 Document 4. Rejected Product 4.1 Isolate & screen 4.2 Repeat 3 times / change orientation 4.3 Investigate – trained personnel / off line 4.4 Identify potential source& resolve 5. Maintain Records 5.1 Test / Production / Maintenance Fortress Technology Ltd. www.fortresstechnology.com