What is the difference between apparent density and bulk density? It would be better to have an exam

Density: Density is the mass of a material per unit volume in an absolutely dense state.

Apparent density: also known as apparent density, refers to the mass of the apparent volume of a material per unit (including the volume of material solids and closed pores) under specified conditions.

Because many porous substances are hollow in the middle, with open holes that communicate with the outside and closed holes that are not open, the volume of the open part that communicates with the outside is removed, and the density that includes the volume of the closed part is called "apparent density". That is: apparent density = mass of the material (volume of the solid part + volume of closed cell).

If the volume of the opening part is not removed, the calculated density is called bulk density.

It is also known as bulk density, apparent gross density, bulk density), that is: bulk density = mass of the material The macroscopic volume of the material (including the volume of the solid part + internal closed pores + open pores).

Bulk density: The weight per unit volume of a bulk material in its natural stacked state is known as bulk density. Generally, it is mostly used on granulated objects.

1. Bulk density: loose bulk density and compacted bulk density. The mass per unit volume includes the inner and outer pores of the particles and the voids between the particles. m/（v。+v+v1+v2）；

2. Apparent density (apparent density): the ratio of the mass of the material to the apparent volume. The apparent volume is the volume of the solid plus the volume of closed pores, which is the volume of water discharged by the material. m/（v+v2）。

3. The above symbols represent the following meanings:

1. v refers to the volume of the particle itself without any empty (porosity);

2、v。refers to the volume of inter-particle voids;

3. v1 refers to the volume of micropores on the outer surface of the particle;

4. V2 refers to the volume of closed pores encased inside the particle.

Fourth, it can be seen that the mass corresponding to the two is the same, but the volume corresponding to the denominator is different, and the bulk density includes all possible volumes; However, the apparent density does not include the volume of the inter-particle voids and the volume of the micropores on the outer surface of the particles, because these are all visible voids, and the only v2 is the volume of the closed pores wrapped inside the particles, which you cannot see with the naked eye, so we call the density calculated according to this formula also called the apparent density, that is, it looks like the true density! If we can determine and subtract the volume of v2, then it is the true density!

The density of the materialApparent densityand the difference between bulk density:

1. The definition of different bulk densities is to fill the dust or powder freely in a certain container, and it is measured after the filling is completedThe volume of a single head modeQuality. Apparent density refers to the ratio of the mass of a material to its apparent volume.

2. Measurement methods for different bulk densities: the mass of bulk materials per unit volume in a stacked state. Calculated as follows:

0=m v 0, where: 0 is the bulk density of the stacking pin, kg m; m is the mass of the material in a certain container, kg; v 0 is the stacked volume of the material.

That is, the volume of the container, m, is the total volume including the voids between the particles and the pores inside the particles. Apparent density: apparent density = mass of the material (volume of the parenchymal part + volume of closed cell) carbon materials are usually pycnometer (pycnometer), toluene orN-butanolIt was determined as a standard solution.

It is also determined by the gas medium displacement method, in which the micropores are filled with helium until almost no adsorption is eliminated. Sometimes mercury is also used.

Pressing into the microwells for filling assays. Depending on the measurement method and the degree of immersion or displacement, the resulting values vary.

3. The main reason is that the different apparent densities of the materials represent the quality of the material unit mesoscopic volume (including the internal closed pores). Bulk density refers to the mass of a bulk or powdery material per unit volume in its natural stacked state. The stacked volume of the material refers to the natural, loose state.

The volume of the container to be loaded in a certain way, including the volume of particles and the volume of the voids between the particles.

1. Definitions. 1. Density is the unit volume of a material in an absolutely dense state.

quality. The so-called volume in the absolute dense state refers to the volume without any pores in the liter Jingshu.

2. Apparent density.

Represents the mass of the material per unit meso-volume (including internal closed pores). Bulk density represents the mass of a material's unit macroscopic volume, including internal closed and open pores.

3. Bulk density.

Refers to the mass of a bulk or powdery material per unit volume in a naturally stacked state. The stacked volume of the material refers to the volume of the container in a natural and loose state according to a certain method, including the volume of particles and the volume of the voids between the particles.

2. Differences. 1. The scope of the expression object is different.

Density is a broad concept that can denote the density of all substances; Apparent density and bulk density refer to the density under specific material conditions.

2. The measurement method is different.

Density determination can be done using the specific gravity cup method, Archimedes' law.

Buoyancy method, density meter.

law, etc. Apparent density: For materials with regular shapes, volume is measured directly; For irregularly shaped materials, the pores can be closed by wax sealing, followed by volume measurement by draining. Bulk density is generally the measured volume mass of an object in a container just after it has been filled.

Both represent the mass of the material per unit volume, and the difference between the number of early servants is that the measurement and calculation of the volume are different.

Apparent densityThe apparent volume of the material (solid land volume + closure) is used.

pore volume) bulk density.

The specific points of the stacked volume of the material (total volume of the material + the volume of the voids between the particles) are used: the apparent volume of the material - the natural state, including closed pores, excluding open pores.

Bulk volume of material – absolutely dry or aqueous, naturally stacked, with inter-particle voids.

1. Density: Density is the mass of a material per unit volume in an absolutely dense state.

2. Apparent density.

Also known as apparent density, it refers to the apparent volume of a material (including material solids and closures) under specified conditions.

pore volume).

Because many porous substances are hollow in the middle, with open pores that communicate with the outside and closed pores that do not communicate with the outside, the volume of the open part that communicates with the outside is removed, and the density that includes the volume of the closed part is called "apparent density". That is: apparent density = mass of the material (volume of the solid part + volume of closed cell).

Bulk density. The weight per unit volume of bulk material in its natural packing state is known as bulk density. Generally, it is mostly used on granulated objects.

Recently, I was looking at civil engineering materials. It doesn't feel like what was said upstairs was entirely correct.

1. Density is the weight per unit volume of a material in an absolutely dense state.

2. Apparent density refers to the weight of a material per unit volume in its natural state. (Note that it is not upstairs that says "does not contain the external porosity of the object").

3. Bulk density refers to the weight per unit volume of powdery or bulk material in a stacked state.

There are three corresponding formulas. This is generally available. If there are too many words, I won't type. Hope.

The word density is relatively general and refers to the mass of an object per unit volume;

Apparent density refers to the mass per unit volume that does not contain the external pores of an object;

Bulk density refers to the mass of objects stacked together per unit volume, including the volume occupied by the gaps between objects;

Bulk density is further divided into tight bulk density and loose bulk density. For example, the determination method of sand and gravel is in JGJ52-2006 or GB14685 and GB14684 standards.

The word density is relatively general and refers to the unit volume of an object.

quality. Apparent density

refers to the mass per unit volume that does not contain the external pores of the object;

The bulk density is large.

refers to the mass per unit volume of objects stacked together, which includes the volume occupied by the gaps between objects;

Bulk density is further divided into tight bulk density and loose stacked dense silver volt. For example, the determination method of sand and gravel is in JGJ52-2006 or GB14685 and GB14684 standard imitations.