Analysis of materials

Claim 1

A device suitable for obtaining from a fluid mixture of first and second component materials a quantity thereof which contains a fixed weight of said first component material, the density of said second component material being known and the mixture containing the two component materials in unknown proportions, which device comprises a cylindrical container, a float, and means for indicating, during use of the device, when the float has reached a fixed height above the bottom of the container, the float having a cylindrical lower portion contiguous with an upper portion, the upper portion being shaped so that its cross-sectional area a x at a height x above the lower portion is defined by the formulae ##EQU7## wherein: A is the known cross-sectional area of the cylindrical container; a x is the cross-sectional area of the float at a height x above the junction of the cylindrical lower portion and the shaped upper portion of the float; v c is the known volume occupied by the cylindrical lower portion of the float; D x is the density of a fluid mixture in which the float floats with the surface of the fluid mixture at a height x above the junction of the cylindrical lower portion and the shaped upper portion of the float D max is the known density of the fluid mixture in which the float floats with the surface of the fluid mixture level with the junction between the cylindrical lower portion and the shaped upper portion of the float, i.e. when x = 0; v x is the known volume of the fluid mixture of density D max in the container when the float floats and is at the fixed height above the bottom of the container; D f is the known density of the second component, i.e. the suspending liquid; D s is the density of the first component, i.e. the fine particulate solid; and W is the weight of said first component per unit volume of fluid mixture. whereby, when a volume of the fluid mixture containing said fixed weight of the first component material has been introduced into the container, the float, over a range of proportions of said first and second component materials, will float at said fixed height above the bottom of the container independently of the relative proportions, within said range of proportions, of the first and second component materials in the fluid mixture.

Claim 2

A device suitable for obtaining from a fluid mixture of first and second component materials a quantity thereof which contains a fixed weight of said first component material, the density of said second component material being known and the mixture containing the two component materials in unknown proportions, which device comprises a cylindrical container, a float, and means for indicating, during use of the device, when the float has reached a fixed height above the bottom of the container, the float having a cylindrical lower portion contiguous with an upper portion, the upper portion being shaped so that its cross-sectional area a x at a height x above the lower portion is defined by the formulae ##EQU7## wherein: A is the known cross-sectional area of the cylindrical container; a x is the cross-sectional area of the float at a height x above the junction of the cylindrical lower portion and the shaped upper portion of the float; v c is the known volume occupied by the cylindrical lower portion of the float; D x is the density of a fluid mixture in which the float floats with the surface of the fluid mixture at a height x above the junction of the cylindrical lower portion and the shaped upper portion of the float D max is the known density of the fluid mixture in which the float floats with the surface of the fluid mixture level with the junction between the cylindrical lower portion and the shaped upper portion of the float, i.e. when x = 0; v x is the known volume of the fluid mixture of density D max in the container when the float floats and is at the fixed height above the bottom of the container; D f is the known density of the second component, i.e. the suspending liquid; D s is the density of the first component, i.e. the fine particulate solid; and W is the weight of said first component per unit volume of fluid mixture. whereby, when a volume of the fluid mixture containing said fixed weight of the first component material has been introduced into the container, the float, over a range of proportions of said first and second component materials, will float at said fixed height above the bottom of the container independently of the relative proportions, within said range of proportions, of the first and second component materials in the fluid mixture.

Claim 5

An apparatus, suitable for determining the proportion by weight of particles of a particulate solid material in suspension in a liquid which are larger than a giver size, which apparatus comprises (i) a device comprising a cylindrical container, a float, and means for indicating, during use of the device, when the float has reached a fixed height above the bottom of the container, the float having a lower portion contiguous with an upper portion, the upper portion being shaped so that its cross-sectional area a x at a height x above the lower portion is defined by the formulae ##EQU8## wherein: A is the known cross-sectional area of the cylindrical container; a x is the cross-sectional area of the float at a height x above the junction of the cylindrical lower portion and the shaped upper portion of the float; v c is the known volume occupied by the cylindrical lower portion of the float; D x is the density of a fluid mixture in which the float floats with the surface of the fluid mixture at a height x above the junction of the cylindrical lower portion and the shaped upper portion of the float D max is the known density of the fluid mixture in which the float floats with the surface of the fluid mixture level with the junction between the cylindrical lower portion and the shaped upper portion of the float, i.e. when x = 0; v s is the known volume of the fluid mixture of density D max in the container when the float flloats and is at the fixed height above the bottom of the container; D f is the known density of the second component, i.e. the suspending liquid; D s is the density of the first component, i.e. the fine particulate solid; and W is the weight of said first component per unit volume of fluid mixture. whereby, when a quantity of the suspension containing a fixed weight of the particulate solid material has been introduced into the container, the float will float at said fixed height above the bottom of the container independently of the relative proportions of the liquid and particulate solid material in the suspension, (ii) means for separating from said quantity of suspension substantially all the solid particles larger than said given size; and (iii) means for determining the weight of said solid particles which are larger than said given size.

Claim 6

An apparatus, suitable for determining the proportion by weight of particles of a particulate solid material in suspension in a liquid which are larger than a giver size, which apparatus comprises (i) a device comprising a cylindrical container, a float, and means for indicating, during use of the device, when the float has reached a fixed height above the bottom of the container, the float having a lower portion contiguous with an upper portion, the upper portion being shaped so that its cross-sectional area a x at a height x above the lower portion is defined by the formulae ##EQU8## wherein: A is the known cross-sectional area of the cylindrical container; a x is the cross-sectional area of the float at a height x above the junction of the cylindrical lower portion and the shaped upper portion of the float; v c is the known volume occupied by the cylindrical lower portion of the float; D x is the density of a fluid mixture in which the float floats with the surface of the fluid mixture at a height x above the junction of the cylindrical lower portion and the shaped upper portion of the float D max is the known density of the fluid mixture in which the float floats with the surface of the fluid mixture level with the junction between the cylindrical lower portion and the shaped upper portion of the float, i.e. when x = 0; v s is the known volume of the fluid mixture of density D max in the container when the float flloats and is at the fixed height above the bottom of the container; D f is the known density of the second component, i.e. the suspending liquid; D s is the density of the first component, i.e. the fine particulate solid; and W is the weight of said first component per unit volume of fluid mixture. whereby, when a quantity of the suspension containing a fixed weight of the particulate solid material has been introduced into the container, the float will float at said fixed height above the bottom of the container independently of the relative proportions of the liquid and particulate solid material in the suspension, (ii) means for separating from said quantity of suspension substantially all the solid particles larger than said given size; and (iii) means for determining the weight of said solid particles which are larger than said given size.