MPFZA-3

The MPFZA-3 is a portable magnetometer from IFA that measures the vertical component of the Earth’s magnetic field in the field and at geomagnetic observatories and records its daily variation [1]. Its Vacquier-type transducer, made at the Centre for Technical Physics in Iași, has an extra winding on a Pyrex glass former for a stable field-to-current conversion; excitation and signal processing are like those of IFA’s space magnetometers, with a dual-slope analogue-to-digital converter, CMOS digital circuits and LM741, LM101 and LM108 operational amplifiers [1]. It measures 0–100,000 nT with a resolution of 1 nT, a basic error of ±10 nT and a temperature drift of 2 nT/°C, working from −5 to +55 °C; it was approved in 1981 (the book also calls it MPZA-3) [1].