Measurement unit for magnetic fields, electrical currents and voltages - uses sensor self-oscillation to exclude current generator noise, suitable for HF over 10 MHZ

摘要

The device is for sensitive measurement of magnetic fields electrical currents, and electrical voltages eliminates the disadvantage of noise sensitivity being defined by the frequency of an external test current generator. For maximum resolution the generator frequency has in the region of the sensor bandwidth. The measurement device frequency is greater than 100 MHz and such high frequency generators with superimposed currents are expensive to produce and generate a great deal of output noise. Consequently, it is simpler to cause the sensor to self-oscillate. This can be achieved by connecting the sensor in parallel with a series circuit contg. a resistor and a coil. The resulting oscillation frequency is widely adjustable and automatically scans the sensor. The current source is unchanged and used for gaining the measurement data and eliminating external noise.