METHOD FOR PREPARATION OF MAGNETICALLY SENSITIVE LIQUID FOR MAGNETIC RECORD FIELDS VISUALISATION AND FOR MAGNETIC-TAPE TESTING Russian patent published in 2009 - IPC G01N27/84 

FIELD: instrumentation.

SUBSTANCE: invention refers to control instrumentation and can be used for magnetic record fields visualisation in magnetic-tape testing and ferrography. Method of magnetically sensitive liquid preparation consists in the following: Oleinic acid is added in portions of 0.1-0.2 ml into the volume of 30-50 ml of kerosene-based magnetic liquid containing magnetite particles with average diametre of 15-17 nm at a temperature of 18-20°C and with constant stirring. When oleinic acid concentration in magnetic liquid reaches 10-12 vol.% quasi-solid spontaneously magnetised aggregations appear. Size of these aggregations does not exceed 2 mcm. Average aggregation size is less than 1 micron. Fine layer of obtained magnetically sensitive liquid is applied on magnetic record media (magnetic diskette, magnetic tape, hard disk).

EFFECT: reducing material and time consumption, increasing stability and resolution capability of obtained magnetically sensitive liquid.

3 dwg, 4 ex