Wiegand sensors are intrinsically safe, functioning without external power sources. No mechanical contact occurs between the source of the alternating magnetic field and the Wiegand wire assembly, meaning no wear. The systems will function reliably for billions of cycles. The rugged sensors can operate over a wide temperature range and are insensitive to electrical noise. Response is consistent over a frequency range of near-zero to over 30 kHz. The sensors are available in package form, consisting of a 15-mm length of Wiegand wire surrounded by a copper coil, all contained in an SMD-mountable plastic support structure.