DEVICE FOR DETEMINING DEGRADATION STATE AND METHOD FOR EVALUATING PAINT COATS SERVICE LIFE

The invention relates to a device for determining paint coats degradation state and to a method for evaluating the service life of paint coats applied on metal surfaces with imposed corrosion protection capacity. According to the invention, the device comprises two connection conductors (F1, F2), i.e. one conductor (F1) connecting the metallic structure (SM), to be analyzed, to the instrument (M) which measures electric resistivity and another conductor (F2) connecting the measuring instrument (M) itself to a measuring probe (D) consisting of a polymeric body (1) provided on its internal part with an electrically conductive graphite disc, electrically connected to the contact conductor (F2), the edge of the body (1) being provided with a sealing ring (3) made of soft silicone rubber ensuring delimitation of the contact surface (S) with the paint by a disc (4) made of a porous material, where, in order to ensure a firm and reproducible electric contact of the porous disc (4) upon successive determinations, it is re-imbibed with solution each time, for compensation of possible losses, the measuring probe (D) as a whole being introduced into an insulating handle (5). The method, as claimed, consists in measuring periodically the values of paint coats electric resistivity at various time intervals to obtain the resistivity variation curve depending on time, extrapolating the resistivity up to the critical value, to obtain the service life of the analyzed paint coat at the imposed parameters. Invenţia se referă la un dispozitiv de determinare a stării de degradare a straturilor de vopsea şi la o metodă pentru evaluarea timpului de viaţă a straturilor de vopsea, aplicate pe suprafeţe metalice, cu capacitate de protecţie anticorozivă impusă. Dispozitivul conform invenţiei este alcătuit din doi conductori (F1, F2) de legătură, un conductor (F1) prin care se conectează la instrumentul (M) de măsură a rezistivităţii electrice structura (SM) metalică de investigat şi un conductor (F2) prin care se conectează acelaşi instrument (M) de măsură la o sondă (D) de măsură formată dintr-un corp (1) din material polimeric care, pe partea interioară, este prevăzut cu un disc din grafit electroconductor, conectat electric la conductorul (F2) de contact, buza corpului (1) fiind prevăzută cu un inel (3) de etanşare realizat dintr-un cauciuc siliconic moale care asigură delimitarea suprafeţei (S) de contact cu vopseaua printr-un disc (4) din material poros, iar pentru asigurarea u