Hirst Magnetics GM07 Gauss Meter, DC and 15 Hz → 10 kHz | RS
Digital Gauss Meter, Magnetic Field Tester Hall Probe Multifunctional Lightweight 2000Gs 25000Gs Low Consumption for Iron Separator : Amazon.co.uk: DIY & Tools
Digital Gauss Meter | Sepor, Inc
Model 2100 Gaussmeter Probes - Magnetic Instrumentation