TY - JOUR
T1 - Apparatus for the electrical characterisation of conductive fluids
AU - Blake-Coleman, Barrie C.
AU - Ulrich, Anna
AU - Fitzpatrick, Paul F.
AU - Calder, Michael R.
AU - Clarke, David J.
PY - 1989
Y1 - 1989
N2 - Non-invasive and fully automated conductimetric measurements of electrolyte and bacterial samples were achieved in a closed volume test cell, comprising a magnetic field coil and detector. By monitoring field induced currents in sample electrolytes the magnitude of the sample current was shown to vary as the inverse of the sample impedance. The impedance characteristic was shown to be that of an LCR resonant circuit. This characteristic is primarily a function of the applied frequency and the solution/cell properties being dependent on the solution conductivity and dielectric permittivity at any given concentration. Small changes in sample dielectric permittivity in the presence of a large background conductivity are shown to be significant. The apparatus described can provide fixed or swept frequency conductivity measurements in the range 1 kHz to 2.25 MHz with a lower conductivity sensitivity of 0.9 × 10-3 Scm-1. Bulk impedimetric characteristics of cell suspensions are derived by a two stage measurement.
AB - Non-invasive and fully automated conductimetric measurements of electrolyte and bacterial samples were achieved in a closed volume test cell, comprising a magnetic field coil and detector. By monitoring field induced currents in sample electrolytes the magnitude of the sample current was shown to vary as the inverse of the sample impedance. The impedance characteristic was shown to be that of an LCR resonant circuit. This characteristic is primarily a function of the applied frequency and the solution/cell properties being dependent on the solution conductivity and dielectric permittivity at any given concentration. Small changes in sample dielectric permittivity in the presence of a large background conductivity are shown to be significant. The apparatus described can provide fixed or swept frequency conductivity measurements in the range 1 kHz to 2.25 MHz with a lower conductivity sensitivity of 0.9 × 10-3 Scm-1. Bulk impedimetric characteristics of cell suspensions are derived by a two stage measurement.
KW - bacterial impedance monitoring
KW - conductivity
KW - electrolyte conductivity
KW - impedance monitoring
KW - non-invasive impediometry.
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U2 - 10.1016/0265-928X(89)80025-2
DO - 10.1016/0265-928X(89)80025-2
M3 - Article
C2 - 2497748
AN - SCOPUS:0024854061
VL - 4
SP - 87
EP - 108
JO - Biosensors and Bioelectronics
JF - Biosensors and Bioelectronics
SN - 0956-5663
IS - 2
ER -