A Metal detector is used to find out and remove small pieces of ferrous, non-ferrous, and SS during tablet compression in pharmaceuticals. Many times, Such types of metal may be entered into the product during the process, for example, worm sieve wires. This is where the metal detector comes into the role to removes such types of contaminants. The Metal Detector Challenge Test is conducted to verify the sensitivity of the metal detector. This device automatically detects and removes contaminants from tablets and capsules during the manufacturing process without causing damage. When contaminants are detected, the pneumatic solenoids activate the reject flap, removing the contaminants from the production line.
Principle of Metal Detector
An electromagnetic induction metal detector consists of one or more inductor coils that interact with metallic elements in the ground. A pulsing current is applied to the coil, which induces a magnetic field. When the magnetic field of the coil moves across metal, it induces an electric current (eddy current) in the metal.
Eddy current induces their magnetic field, which generates an opposite current in the coil, which induces a signal indicating the presence of metal. The metal detector consists of an oscillator that produces an alternating current. It also contains a receiver coil.
The modem of Metal Detector is based on:
- VLF-Very low-frequency
- PI-Pulse Induction
- BFO-Beat Frequency oscillation
- VDI-Visual discrimination indicator
- Sensitivity of Metal detector: 100 Food grade plastic flap Sensitivity, timer, and phase setting
Metal Detector challenge test kit
- Fe (Ferrous)- 0.15 mm
- N-Fe (Non-Ferrous)- 0.25mm
- S.S.( Stainless steel AISI 316)- 0.25mm non-magnetic
- Dummy: Without metal particles and has no diameter
Challenge Test Procedure for Metal Detector:
- Switch on the power supply, now passes the dummy sample. It should be a pass.
- Then pass SS, Fe, and Non-ferrous one by one. It should be rejected.
Note: If the metal detector test failed, immediately stop the machine and inform the head of the department and QA Department and immediately raise a request for breakdown. Put the “under breakdown” label on the metal detector.
Frequency of challenge test:
- At the start of the batch and then every two hours alternatively by production and QA.
- End of a batch by Production and QA.
- After the breakdown.
Metal detector challenge test for Capsule:
Metal Use to do the challenge test for the Capsule is:
- Fe (Ferrous)- 0.60 mm
- N-Fe (Non-Ferrous)- 0.80mm
- SS( Stainless steel AISI 316)- 1.00mm non-magnetic
- Dummy: Without metal particles and has no diameter
Follow the above Procedure to do the challenge test for Capsule.
