Time and frequency dependence of disposable ECG electrode-skin impedance

Med Instrum. 1979 Sep-Oct;13(5):269-72.


The magnitude and phase of disposable electrode-skin impedance were studied as functions of time, 0-48 hours, and frequency, 1 Hz-1 kHz. For both unabraded and mildly abraded skin, the impedance decreased as a function of time steadily or exponentially with time constants of several hours. Impedance decreased as a function of frequency by factors of 2 to 20 with greatest change at low frequencies. For heavily abraded skin, the impedance decreased slightly and then increased as a function of time especially at low frequencies. Impedance imbalance between pairs of identical electrodes applied in a like manner to the forearm were often greater than k omega, nearly equal to individual electrode-skin impedances, and decreased with time. Electrode impedance imbalance is particularly important because it affects noise levels in ECG recordings.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Chlorides
  • Disposable Equipment
  • Electric Conductivity*
  • Electrocardiography / instrumentation*
  • Electrodes*
  • Electronics, Medical / instrumentation
  • Gels
  • Humans
  • Silver
  • Skin / anatomy & histology
  • Skin Physiological Phenomena*
  • Time Factors


  • Chlorides
  • Gels
  • Silver