To calculate bulk density and skeletal density using a mercury intrusion meter

Factory direct 0603 emerald green, 0603 green (0.6 thickness) a lot of low price

Probe current voltage pin 420*4450 head diameter 5.0 over current current and voltage pin

0.8A 1000V rectifier bridge stack

TP-IP4220CZ6 5V 0.35PF breakdown voltage 6V SOT

The AutoPore mercury intrusion method is commonly used to determine the total pore volume of a sample, and the accuracy of the test results can be less than 1%. In addition, the mercury intrusion method can also be used to calculate the bulk density and skeletal density of a sample. Obviously, the mercury intrusion method is not capable of directly measuring the density, but performing a volume test, and then calculating the density according to the quality provided by the operator.

Calculation process:

One of the deviations in skeletal density and bulk density comes from equation (1). Equation (1) is a simplified equation for placing a porous material in a dilatometer assembly for bulk density calculation. The internal volume of the dilatometer, including the volume of the rod and capillary, can be predetermined by the process of filling the mercury and weighing. Assuming that the sample has been placed in the dilatometer, the mercury has been filled to fill all remaining space except the sample. The equation is written:

Vs(B) = Vpen – VHg (1)

Here:

Vs(B): the bulk density of the sample

Vpen: total internal volume of the dilatometer

VHg: the volume of space occupied by mercury

A whole range of quality data is required throughout the testing process. The mass of the air dilatometer assembly, the dilatometer assembly contains the mass of the sealing hardware, the mass of the dilatometer assembly that is sealed after the sample is placed, and the quality of the sealed dilatometer assembly after the sample is filled and filled with mercury. From these quality data, the volume of space occupied by mercury can be obtained:

VHg = WHg / Hg (2)

Here:

WHg = quality of filled mercury

Hg=25F mercury density (13.5335g/cc)

The quality of mercury is:

WHg = WPSHg - Wpen – Ws (3)

Here:

WPSHg = total mass,

Wpen = dilatometer and hardware quality

Ws = sample quality

WPSHg and Ws are added by the operator and are deducted from the total mass.

Lianli (3) and (2), available:

VHg = WPSHg - Wpen - Ws / Hg (4)

Substituting (4) into (1) gives:

Vs(B) = Vpen - [ WPSHg - Wpen - Ws / Hg ] (5)

The bulk density s(B) can be calculated by dividing the sample mass Ws by Vs(B).

s(B) = Ws / Vs(B) (6)

From the heap volume, the total pore volume filled with mercury is subtracted to obtain the skeleton volume, Vs(S):

Vs(S) = Vs(B) – Vp (7)

The report generally yields the pore volume per gram of material, Ps. The total pore volume can be calculated by multiplying Ps by the total mass.

Vs(S) = Vs(B) – WsPs (8)

The skeletal density s(s) can be calculated by dividing the mass of the sample by the total pore volume.

s(s) = Ws / Vs(S) (9)

Error Analysis

There are some errors in calculating the density using the mercury intrusion method, and sometimes even erroneous result data. The reason for the problem data is mainly from equation (5). Because Vs(B) is subtracted from two extremely small, almost equal numbers. These numbers are usually more than ten times larger than Vs(B). Therefore, the 1% error will become 10%. Also, all data used to calculate Vs(B) is obtained through the weighing process. (Vpen calculates this mass by dividing the density of mercury at room temperature by weighing a mercury-filled dilatometer.)

The main opportunity for the instrument to influence Vs(B) is the filling process. If the dilatometer is not fully filled, the volume of the difference will be divided into sample volumes. In addition, the difference in temperature also causes a slight error because in some instruments, the density of mercury at 25 ° C is uniformly assumed to be a constant 13.5335. After the start of the test, pressure is required for the pore size test, which also affects the volume of the heap, because at higher pressures, mercury gradually fills into the smaller pores. If the material has a significant pore volume distribution in the 100 micron range, a higher accuracy and repeatability of the initial pressure is required to obtain reproducible stack volume test results.

The measurement accuracy of the skeletal density Vs(S) depends first on the accuracy of Vs(B), followed by the accuracy of the pore volume test.

The main reason for the inconsistency of the tested skeletal density and the manual value is that there are some closed pores in the material that mercury cannot enter, some pores that cannot enter even under high pressure conditions, and the compression of the sample. For organic materials, compression is particularly noticeable. When the plastic material is at 60,000 psi, the volume can be reduced by up to 10%, accompanied by a change in density.

Recommended operation

Use the following recommended actions to minimize the error:

1. Ensure the accuracy of the weighing, at least to the nearest five decimal places

2. Accurately determine the internal volume (rod and capillary) of the dilatometer, preferably to the nearest five decimal places. Make sure to use the same sealing cap all the time, because the switch is used, it will cause a certain internal volume measurement error.

3. Occasionally check to make sure the dilatometer is properly filled.

4. Avoid accurate density testing when the temperature of the dilatometer changes significantly.

5. Try to use as many samples as possible to maximize the actual volume of the sample in the dilatometer.

6. Carefully check the quality information entered before each run to prevent errors.

7. Detect the pore volume distribution curve at a large slope at the beginning and end of the test. This makes it difficult to get repeatable data. The slope at the end of the high pressure may be caused by the destruction of the closed pores of the sample or the compression of the sample.

Transfer from "Application Note-Bulk and Skeletal Density Computations for the AutoPore"

Original link: http:// AA%A8%E6%A0%BC%E5%AF%86%E5%BA%A6%E3%81%AE%E8%A8%88%E7%AE%97_AutoPore_20120514.pdf

Fully automatic mercury intrusion aperture analyzer AutoPore IV series

AutoPore IV Series Mercury Injector

Provides a faster and more accurate measurement of the pore size distribution of the material (0.003-1100 μm) than other methods. The instrument enhances the performance of the data required to characterize the pore structure of solid materials with higher precision. New data processing and reporting options have also been added to provide more information on material hole geometry and fluid permeability.

Features:

• Large pore pressure range: 0.2-50 psi, providing a pressure increment of 0.05 psi for detailed data collection in large pores

• The fast scan mode allows continuous pressure to increase to near equilibrium, enabling rapid screening of AutoPore's high repeatability and reproducibility, allowing it to detect subtle but important differences between samples. Thanks to its high repeatability, users can use this technique to screen samples and compare their deviations from the parameters on the product specifications.

• The measurement resolution of mercury and mercury withdrawal volume is extremely high, better than 0.1μL

• The choice of baseline correction procedure (automatic, differential or manual) corrects mercury compression and thermal effects from high pressure

• Different pressurization modes can be selected: fast scan mode, user demand setting or more precise and more detailed balance mode

• Users can set fewer pressure points to collect data. However, if the maximum mercury inflow volume increment function of the instrument is used, if the amount of mercury entering the adjacent pressure point exceeds the incremental value during the analysis, the instrument will automatically increase the data point between two points.

• A variety of pore volume, pore area and pore size curves, as well as total mercury volume, total pore specific surface area, median pore diameter, average pore size, bulk density and apparent (skeletal) density