An automatic measurement apparatus for low value magnetic flux with high resolution

When a low value flux is to be measured, the induced signal in the measuring coil would be very weak and the instrument resolution thus becomes very important (Chen Duoxingr, Magnetic field Measurement, Beijing, 1985). Here a nanovoltmeter is used as the preamplifier to detect the induced signal from the measuring coil and is followed by a digital integrator to obtain the flux value. Thus a resolution of less than 1 nWb for flux measurement is attained.