METHOD FOR ESTIMATING DISTRIBUTION DENSITY OF OPEN CRACKS OVER SURFACES OF ROCK SAMPLES Russian patent published in 1994 - IPC

FIELD: practical geology, measurement technology. SUBSTANCE: sample of rock is made into a cube; from photographic film are cut pieces corresponding in form and size to the faces of the sample in the presence of light; the sample is treated with normal solution of sodium sulfide in a vacuum. The film pieces with normal solution of sodium sulfide in a vacuum. The film pieces with the emulsion side presented to the sample are applied to and pressed against the sample surfaces. In response to pressure on all sides a quantity of liquid is squeezed the hollow space of the sample to its periphery and comes into contact with the photographic film, and in consequence sodium sulfide and silver chloride contained in the emulsion layer to yield dark-colored silver sulfide above mouths of cracks. At the close of reaction, the sample is got out of the device, the film pieces are peeled off the sample and are treated with a fixing agent; in doing so, silver chloride is removed, whereas silver sulfide remains in the emulsion layer, laying-out the crack mouths. Washed and dried film pieces are used to make photographic prints by which the distribution density of open cracks over surfaces of rock sample is estimated with known methods. EFFECT: simplified estimation process.