|METAL DETECTOR CONTROL BOARD|
|CO-EL srl - J.Peri 61/61A - 41122 Modena - tel: 0039/059/282360 - fax: 0039/059/284429 - mail: firstname.lastname@example.org|
How should a metal detector be installed?
All CO-EL metal detectors work with a balanced magnetic field, controlled by a control board that discriminates between the variations induced by metallic impurities and variations induced by the product to be checked. To avoid false alarms, it's necessary to eliminate all the causes of variation in the magnetic field:
Distance of nearby metallic parts
For this reason, the "detection zone" is bigger than the opening of the metal detector, and must be kept free from metal parts.
When installing a metal detector head, every fixed metal part must be kept at a distance at least equal to the passage height.
Every moving metal part must be kept at a distance at least equal to 1.5 times the passafe height instead.
Metal detector head installed on a conveyor belt
CO-EL metal detectors are supplied with plastic feets to keep the metal detector head insulated from the conveyor's frame. Feets unproperly mounted may lead to false alarms.
The belt must slide on a non-conductive plane. A belt rubbing for long time on a metallic plate may be contaminated by metallic impurities, generating false alarms. To avoid electrostatic pertutrbations, we recommend the use of and antistatic conveyor belt.
If the structure is poorly fixed, an electromotive force may be generated that unbalances the metal detector's field provoking a false alarm.
To avoid this all conductive parts composing the metal detector conveyor stucture must be welded or well fixed. For these reasons it's necessary to use plastic rollers; if it is not possible, mount rollers with an insulating bearing: one roller's side must be kept conductive to eliminate electrostatic discharges.
Metal detectors alimentari