2.2.6 spase://CDPP/Instrument/AMDA/IMP8/MAG MAG IMP8 MAG 2010-02-04T12:34:56.789 The magnetic field experiment on the IMP-8 spacecraft utilizes a tri-axial fluxgate (saturable inductor) magnetometer. The instrument originally had three, automatically determined, ranges, +/-12 nT, +/-36 nT, and +/-108 nT, full scale. Because of a range-change circuit failure occurring in early July 1975, the experiment was commanded into a fixed +/-36 nT range on July 11, 1975 at 12:55:09 UT and has been in that range ever since. The measurements are A-to-D converted onboard, to an 8-bit resolution, yielding +/-0.14 nT quantization sensitivity, which is larger than the intrinsic sensor noise level of 0.025 nT RMS. The data from the two-bit (per component) adaptive delta modulator, incorporated into the instrument, and applied to the intrinsic sample rate of 25 vectors/sec., was never utilized, and hence the rate of the full (8-bit) vector words, which occur every 320 ms, represents the effective sample period of the instrument. The sampling rate is synchronized to the spacecraft clock; the basic spacecraft clock frequency is 6.4 kHz. The sensor unit is mounted on the end of a boom approximately 4 m from the center of the spacecraft. User will acknowledge the IMP-8 magnetometer team in any publication resulting from the use of these data. spase://SMWG/Person/Adam.Szabo PrincipalInvestigator IMP-8 Magnetometer Home Page http://lepmfi.gsfc.nasa.gov/mfi/imp8/imp8_hm.html A web site hosting IMP-8 magnetic experiment instrument information as well as web utilities for plotting and downloading data. NSSDC's Master Catalog http://nssdc.gsfc.nasa.gov/nmc/experimentDisplay.do?id=1973-078A-01 Information about the Magnetic Field Experiment experiment on the IMP 8 mission. Magnetometer Magnetic Field Experiment spase://CDPP/Observatory/AMDA/IMP8