We manufacture, export and supply Digital Gaussmeter, DGM-401 to our clients in Roorkee, Uttarakhand, DGM-401 operates on the principle of Hall Effect in Semiconductors. A semiconductor carrying current develops an electromotive force, when placed in a magnetic field, in a direction perpendicular to the direction of both electric current and magnetic field. The magnitude of this e.m.f. is proportional to the field intensity if the current is kept constant. This e.m.f. is called the Hall Voltage. The small Hall Voltage is amplified through a high stability amplifier so that a millivoltmeter connected at the output of the amplifier can be calibrated directly in magnetic field unit (gauss). In the AC range and rms to dc conversion circuit displays the rms value of the field.