Profile: Hirst Magnetic Instruments Ltd. is a manufacturer of magnetising systems, including magnetisers and demagnetisers. Our product line includes magnetisers, demagnetisers, electromagnets and flux meters. We design and manufacture magnetising systems capable of magnetising permanent magnets and assemblies containing permanent magnet. Our models are available in each range suitable for magnetising any suitable material including neodymium iron boron, strontium ferrite and barium ferrite. Our MCSD series of precision magnet charger setter demagnetisers has been designed for a flexible magnet processor for the laboratory and as the production workhorse where calibrating (stabilising, setting or ageing) all types of permanent magnets is required. These units offer functions that are known by various names including magnet treaters, magnet setters, magnet agers and magnet calibrators. The demagnetising fixture is the mechanical interface between the component to be demagnetised and the demagnetiser. The fixture produces the specific magnetic field pattern that is required for that particular application. Our demagnetising fixtures usually consists of a simple coil arrangement where the part to be demagnetised is placed inside the coil. The fixture may have a round or rectangular aperture and may be in a vertical or horizontal orientation to allow easy loading of the containers.