PD 6519-1:1995

Committees responsible
National foreword
Introduction
Guide
1. General
1.1 Scope and object
1.2 Normative reference
1.3 Definitions
2. Electrical impedance of the human body
2.1 Internal impedance of the human body
2.2 Impedance of the skin (Zp)
2.3 Total impedance of the human body (ZT)
2.4 Initial resistance of the human body (Ro)
2.5 Values of the total impedance of the human body (ZT)
2.6 Value of the initial resistance of the human body
      (Ro)
2.7 Dependence of body impedances on the surface area
      of contact for a.c. 50/60 Hz and for d.c.
3. Effects of sinusoidal alternating current in the
      range of 15 Hz to 100 Hz
3.1 Threshold of perception and threshold of reaction
3.2 Threshold of let-go
3.3 Threshold of ventricular fibrillation
3.4 Other effects of current
3.5 Description of the time/current zones (see figure 14)
3.6 Application of heart-current factor (F)
4. Effects of direct current
4.1 Threshold of perception and threshold of reaction
4.2 Threshold of let-go
4.3 Threshold of ventricular fibrillation
4.4 Other effects of current
4.5 Description of the time/current zones (see figure 15)
Annexes
A. (normative) Measurements made on living and dead
      human beings and the statistical analysis of the
      results
B. (normative) Influence of frequency on the total
      body impedance (ZT)
C. (normative) Total body resistance (RT) for direct
      current
D. (normative) Measurements of the dependence of the
      total impedance of the human body (ZT) on the
      surface area of contact
E. (informative) Bibliography
Tables
1. Total body impedance ZT for a current path hand to
      hand a.c. 50/60 Hz, for large surface areas of
      contact
2. Total body resistance RT for a current path hand to
      hand, d.c. for large surface areas of contact
3. Electrodes used for the measurement of the
      dependence of the impedance of the human body ZT
      on the surface area of contact
4. Time/current zones for a.c. 15 Hz to 100 Hz
5. Heat-current factor F for different current paths
6. Time/current zones for d.c.
Figures
1. Impedances of the human body
2. Internal impedances of the human body
3. Simplified schematic diagram for the internal
      impedances of the human body
4. Statistical values of total body impedances valid
      for living human beings for the current path hand
      to hand or hand to foot, for touch voltages up to
      5000 V for a.c. 50/60 Hz
5. Statistical values of total body impedances valid
      for living human beings for the current path hand
      to hand or hand to foot, for touch voltages up to
      220 V, for a.c. 50/60 Hz and d.c.
6. Values of total body impedance ZT measured on 10
      living human beings with a current path hand to
      hand and large contact areas for a touch voltage
      of 10 V and frequencies from 25 Hz to 20 kHz
7. Values of total body impedance ZT measured on one
      living human being with a current path hand to hand
      and large contact areas for a touch voltage of 25 V
      and frequencies from 25 Hz to 2 kHz
8. Frequency dependence of the total impedance ZT of
      a population for a percentile rank of 50% for touch
      voltages from 10 V and 1000 V and a frequency range
      from 50 Hz to 2kHz for a current path hand to hand
      or hand to foot
9. Dependence of the alterations of the human skin on
      current density and duration of current flow
10. Dependence of the total impedance of the human body
      on the surface area of contact and the touch voltage
      (50 Hz)
11. Dependence of the total impedance of the human body
      on the touch voltage for a current path from the
      tips of the right to the left forefinger for a.c.
      50 Hz and d.c. for surface areas of contact of
      approximately 250 mm squared
12. Occurrence of the vulnerable period of ventricles
      during the cardiac cycle
13. Triggering of ventricular fibrillation in the
      vulnerable period. Effects of electrocardiogram
      (ECG) and blood pressure
14. Time/current zones of effects of a.c. currents
      15 Hz to 100 Hz
15. Time/current zones of effects of d.c. currents

Guidance on the effect of a.c. (frequencies between 15 and 100 Hz) and d.c.