METHOD OF TESTING ENCLOSURES FOR TIGHTNESS Russian patent published in 1994 - IPC

FIELD: testing technology. SUBSTANCE: layer of powder indicator compound is applied to inner surface of bottom. Compound consists of chalk (20 to 30 parts by mass), soda ash (20 to 30 parts by mass) and methyl orange (1 to 2 parts by mass). Test liquid - solution of nitric acid (1 to 50 f/lit) - is applied to outer surface of enclosure. In case of through defects, penetration of test liquid under enclosure bottom results in reaction of test liquid with powder indicator and in formation of intensively colored foamy cap over defect. Powder indicator compound if fire-safe, is easily applied to and removed from surface and test liquid is noncorrosive for material of articles being tested. EFFECT: enhanced efficiency of test and improved reliability of test results. 1 tab