Metal Detection, Sensing and Electromagnetic Discrimination

Metal Detection, Sensing and Electromagnetic Discrimination

WRL Consultancy possesses background experience in industrial metal detectors, has designed for special detection and discrimination applications and detector geometries, and is also familiar with low-cost designs.

We provide clients with a custom design service and troubleshooting/improvement of existing designs.

For a new design, the details of the application and its various specific requirements (explicit and implicit) determine key design parameters. For example, some considerations relating to checking of material on a conveyor are: the nature of the material(s)/product(s) being checked, and the variability of their electromagnetic characteristics; the nature of the foreign material(s) to be checked for; the kinds of discrimination required; the construction of the conveyor; the geometrical aspects of the conveyor, material and foreign material; the realistic level of sensitivity required; speed of the conveyor; vibration and EMI environment; cost; value of what is being protected; required reliability-level of detection; standards.

These considerations inform the choice of operating mode – whether continuous-wave detection or pulsed-mode detection. For continuous-wave we then have the choice of frequency (or frequencies) – Hz to MHz. And for pulsed-mode we have magnitude of pulse, the sharpness of its transition,  the sampling rate and duration of sampling. These parameters and consideration of the signal-to-noise ratio inform the determination of: the appropriate electronic architecture; coil/antenna architecture; signal-processing algorithm for the detector; adjustment/calibration methods and systems.

Our capability includes: concept development from the initial brief, electromagnetic modelling/analysis, coil design, analogue and digital signal processing, controls, software/firmware, communications, drive circuits, PCB layout, control of noise/interference effects, EMC control, and mitigation of the signal produced by shielding.

We are pleased to provide advice and perform feasibility work, site visits, concept development and full development with ongoing support, test development and emissions/EMC compliance.