Abstract: A magnetic anomaly detector for detecting the presence of ferrous metal objects such as firearms, knives, or other weapons. The detector contains a square wave generator, a sensor for sensing ferrous metal objects, a sensor amplifier, a main amplifier, and a display. When a ferrous metal object is detected by the sensor, the resultant anomaly in the magnetic field causes portions of a pulse train being input to the sensor amplifier extend past a preset threshold, causing an average input value of an integrator to change. The integrator then forces the average input value of the waveform to zero over an extended period of time to compensate for the changes in the magnetic field. The value at the integrator input represents the magnetic anomaly. The anomaly is also visually displayed in an LED bar graph display for easy detection of weapons by the operator.