principle : if a steel needle is driven by a constant speed electrode through the hl from the exterior , it is possible to measure and catalogue specific resistance variations by means of synchronic recording following derivation from the alternating current circuit against an indifferent electrode per needle electrode through the hl , i.e . from the point of skin surface contact to that of the living `` '' ell layer of the epidermis . descriptions : the mechanical construction consists of a hydraulic trust with a measuring head which is affixed by subpressure to the skin surface .
C0221921
hl
C0014520
epidermi