A COMPUTER-CONTROLLED ALL-PASS PHASE-SHIFT FILTER FOR A VARIABLE FREQUENCY 2-PHASE AC MAGNETIC SUSCEPTOMETER

Authors
HALL DB KNOP JM AYERS SM KLEMME GA SCHREIBER GA
Citation
Db. Hall et al., A COMPUTER-CONTROLLED ALL-PASS PHASE-SHIFT FILTER FOR A VARIABLE FREQUENCY 2-PHASE AC MAGNETIC SUSCEPTOMETER, Review of scientific instruments, 64(11), 1993, pp. 3328-3329
Citations number
3
Categorie Soggetti
Physics, Applied","Instument & Instrumentation
Journal title
Review of scientific instruments → ACNP
ISSN journal
00346748
Volume
64
Issue
11
Year of publication
1993
Pages
3328 - 3329
Database
ISI
SICI code
0034-6748(1993)64:11<3328:ACAPFF>2.0.ZU;2-A
Abstract
A well-established method for the accurate measurement of small change s in ac magnetic susceptibility is to initially null and then monitor the output of the susceptometer as various parameters are modified. Us e of a computer-controlled phase shift filter has allowed us to build a system that will introduce virtually orthogonal signals to compensat e for the in-phase and out-of-phase components of the output. The syst em described is designed for use over the frequency range 50 Hz-4 kHz. Extended frequency ranges are possible with only slight modifications .