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Measuring the Density of Ferrite Cores

IP.com Disclosure Number: IPCOM000091388D
Original Publication Date: 1968-Jan-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Buchanan, RC: AUTHOR [+3]

Abstract

A calibrated liquid column is employed to measure the density of ferrite cores and similar components of small size, fixed shape and high density.

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Measuring the Density of Ferrite Cores

A calibrated liquid column is employed to measure the density of ferrite cores and similar components of small size, fixed shape and high density.

The density of materials of the size, shape and high density of ferrite memory cores is very difficult to determine with any accuracy by conventional geometric or flotation techniques. In the geometric case, the sizes are too small to permit accurate determination of the volumes even if the weights can be determined with reasonable accuracy. For the more accurate flotation or sink float technique, suitable liquids are not readily available. An alternate and reasonably accurate approach is to use the Stokes relationship for the rate of fall of a body in a viscous medium which, under controlled conditions, accurately relates the time required for a sample to fall a given distance to its density.

Cores 11 whose densities are to be measured, are dropped individually into sedimentation column 12 of glass tube 13 containing a 3/1 water/glycerol solution
14. Column 12 is 1 meter long with a capillary diameter of 1.7mm. Solution 14 has a specific gravity of 1.007 gm/cm/3/ and viscosity of 1.82 centipoises at 25 degrees C.

Samples are timed over a standard distance, typically 74.6 cm., via a pair of electric or magnetic sensing coils 15. Calibration is made against metal cores of known densities and identical size and shape.

Density values obtained are in the range of 4.74 gm/cm/3/, are hi...