A position monitoring device including: a first module including at least one magnetic field transducers; a second module including at least one magnetic field generating device; the first and second modules are arranged to be mounted to fixed and moveable objects respectively; the device is operable in a configuration mode wherein it stores configuration data representative of the output of the at least one magnetic field transducers when the first and second modules are aligned; the device is operable in a monitoring mode wherein the output of the at least one magnetic field transducer is compared to the configuration data; if the outputs of the at least one magnetic field transducer deviates from the configuration data by more than a pre-determined amount then the device is arranged to provide an output signal that is indicative of an alarm condition.
