non-destructive testing based on using a low-viscosity liquid containing a dye; used to detect surface discontinuities such as cracks and laps in both magnetic and nonmagnetic materials (see: red dye penetrant test), mittepurustava kontrolli meetod purunenud detaili uurimiseks, mille korral detaili pinnale pihustatud penetrant läbib praod ja detaili vastasküljel saab avastada penetrandiga küllastunud praod (vt kontrastvärvkapillaarkatse)