A magnet assembly (200) is provided that comprises a magnet keeper (204) configured to hold at least one magnet (202). The bracket (208) is configured to receive the magnet keeper (204) and also configured to be attachable to a flowmeter (5) sensor assembly (10). A first surface (216) is formed on the magnet keeper (204), and a second surface (218) is formed on the bracket (208), wherein the first and second surfaces (216, 218) are configured to mate so to provide a radial alignment of the magnet keeper (204) that is within a predefined radial tolerance range.