Air Permeability Apparatus

ASTM (1994) Test method for fineness of Portland cement by air permeability apparatus. American Society for Testing and Materials, Annual Book of ASTM Standards, vol 04.02, West Conshohocken, PA, C204,p 316... 

Fisher Sub-Sieve Sizer. An air-permeability apparatus for the measurement of particle sizes between 0.2 and 50 pm. (Fisher Scientific Co., USA). 

Rigden s Apparatus. An air-permeability apparatus for the determination of the specific surface of a powder air is forced through a bed of the powder by the pressure of oil displaced from equilibrium in a U-tube. (P. J. Rigden, J. Soc. Chem. Ind., 62,1, 1943.) The apparatus is essentially the same as that used in the blaine test (q.v.). 

C 204 Test Methods for Fineness of Hydraulic Cement by Air-Permeability Apparatus C 219 Terminology Relating to Hydraulic Cement C 305 Practice for Mechanical Mixing of Hydraulic Cement Pastes and Mortars of Plastic Consistency C 465 Specification for FVocessing Additions for Use in the Manufacture of Hydraulic Cements C 778 Specification for Standard Sand C 786 Test Method for Fineness of Hydraulic Cement and Raw Materials by the 300-nm (No. 50), 150-pm (No. 100), and 75-nm (No. 200) Sieves by Wet Methods lEEE/ASTM SI 10 Standard for Use of the International System of Units (SI) The Modern Metric System... 

C 204 Test Method for Fineness of Hydraulic Cement by Air Permeability Apparatus ... 

One microliter of this ligation mixture is added to 10 pL of JM109 competent cells, and is left on ice for 30 min in a 96-well plate. Then heat-shock is applied to the cells by placing the 96-well plate at 42°C for 45 s using a heat block incubator such as a PCR apparatus. The plate is then immediately placed on ice for 2 min, after which each transformation reaction mixture is transferred into 100 pL of SOC medium in a 96-well culture plate. The plate is sealed with an air-permeable sheet and incubated at 37°C for 60 min with gentle shaking. 

The specific surface area of eement is eommonly determined directly by air. permeability methods. In the Lea and Nurse method (LI 5). a bed of cement / of porosity 0.475 is eontained in a cell through which a stream of air is f passed, and steady flow established. The specific surface area is caleulated ( from the density of the eement, the porosity and dimensions of the bed of j powder, the pressure differenee aeross the bed, and the rate of flow and ] kinematie viscosity of the air. In the Blaine method (B36), a fixed volume of I air passes through the bed at a steadily deereasing rate, whieh is controlled / and measured by the movement of oil in a manometer, the time required i being measured. The apparatus is ealibrated empirically, most obviously / using a cement that has also been examined by the Lea and Nurse method. The two methods gave elosely similar results. The Blaine method, though not absolute, is simpler to operate and automated variants of it have been devised. 

Considerable testing was done in the laboratory to evaluate the permeability properties of sand-asphalt-sulfur mixes. A constant head air permeameter, similar to the apparatus described in Ref. 9, was used. The coefficient of air permeability criterion below which mixes are con-... 

To measure the concrete cover depth required to prevent carbonation from reaching the steel it is therefore necessary to measure the air permeability and the relative humidity, and then calculate D. This can be done with a proprietary apparatus developed by Parrott and available commercially. Gas and air permeability measurements are discussed in Kropp and Hilsdorf (1995). 

For a new concrete mix or structure, the prediction of carbonation rate is complicated by the lack of data to extrapolate. In a series of papers (Parrott and Hong, 1991 Parrott, 1994a and b), a methodology was outlined for calculating the carbonation rate from air permeability measurements with a specific apparatus, Parrott analysed the literature (Parrott, 1987), see Section 3.U1, and suggested that the carbonation depth D at time t is given by ... 

Blaine air permeability testing apparatus (ASTM C 204-51) for determining the specific surface of powders, with permeability cell made of stainless steel, mounted on lacquered rough-service steel plate, with suction fan, filling funnel, 1 set of filter papers, 1 bottle of oil and 1 thermometer graduated in 0.1 C. calibration sand (approx. lOOg), officially certified ... 

Blaine air permeability testing apparatus (ASTM C 204-51) for determining the specific surface of powders, complete, calibration sand (approx. lOOg), officially certified ... 

Blaine, R. L. (1943). A Simplified Air-Permeability Fineness Apparatus . ASTM Bulletin, 51-55. 

Gostick et al. [212] designed an apparatus in which the in-plane permeability was measured as a function of the DL thickness with different compression pressures (see Figure 4.25). The DL specimen was compressed between plates, which had spacers of different thicknesses in order to control the total thickness in each test. The sample was located between two grooves or channels, one of which corresponded to the inlet of the air and the other to the air outlet. Therefore, the air had to flow in plane through the sample in order to... 

Feser et al. [214] used a radial flow apparatus to determine the viscous in-plane permeability of differenf DLs af various levels of compression (see Figure 4.26). A stack of round-shaped samples, wifh each layer of material separated with a brass shim, was placed inside two plates. Thicker shim stock was also used in order to control the total thickness of the stack of samples. Compressed air entered fhe apparafus fhrough the upper plate and was forced through the samples in the in-plane direction. After this, the air left the system and flowed through a pressure gage and a rotameter in order to measure the pressure drop and the air flow rate. The whole apparatus was compressed using a hydraulic press for each compression pressure, 10 different flow rates were used. 

Nguyen et al. [205] used a technique in which a constant mass flow rate of water-saturated air was forced through a water-saturated sample. It was explained that the shear force of the gas flow dragged water out of the sample. In addition, the saturated air was needed in order to prevent water loss from the sample by evaporation. Once a steady state was achieved, the pressure difference between the inlet and outlet of the apparatus was recorded. After the tests were completed, the sample was weighed to obtain its water content. Thus, the relative permeability was calculated from the pressure drop, the water content in the sample, and the mass flow rate [205]. 

In this connection, a series of steady state displacement tests were conducted in a 170-200 mesh bead pack with a porosity of 0.4 and an absolute permeability of 7000 md. The experimental apparatus is shown in Figure 7. Two types of gas injection were employed - constant pressure injection and constant rate injection air was used in the former, nitrogen in the latter. The liquid phase was water plus surfactant (0.25% by volume Amphosal CA, Stepan Chemical Company) and was always injected under constant... 

It turns out that most polymers are more permeable to O2 than to N2. Let s see how this fact can be exploited to enrich the oxygen content of air. Consider the apparatus at right, which has one feed and two product streams. One of the product streams has been pulled through a polymer membrane with a vacuum pump. 

In the experiment reported here, slurry was added in six stages. After a graded filter cake had been formed, a piston was inserted into the cylinder of the apparatus, producing the compression permeability cell shown. The cake was compressed by applying mechanical pressure to the piston. The compressed cakes were air dried and then baked in an electrically powered reducing furnace. 

The airflow permeability can be used to gain an insight into the structural or physical properties of the cellular materials. The apparatus used is shown in Fig. 16. It comprises a cell into which the specimen can be placed and a method by which a steady flow of air through the specimen can be achieved. This steady airflow can be controlled to give different values, and hence K can be deduced. 

Various sedimentation and elutriation methods are available but these are of value only after standardization for a given type of powder or gel with constant aggregate density. The same applies to measurement of permeability to a stream of air or liquid. The external surface area of porous aggregates, which is an indirect measure of aggregate, size, can be measured by ambient pressure permeametric measurements. Gas is forced through a bed of powder and the flow rate and pressure drop are measured. The apparatus that is used for the flow method of measuring surface area by nitrogen adsorption (Quantasorb from Quantochrome Corporation) can be adapted to this measurement. 

Apparatus has been developed in the Bureau of Standards (F. Carson (i) also (7)) for measuring the permeability of papers, fibreboards, and leathers (section C of Fig. 132). Instruments have also been described (8) for measuring permeabilities of fabrics and textiles, of even smaller impedance to air flow. Fig. 134 illustrates the permeameter of Schiefer and Best (9). The fabric pressure gauge is inclined at a slope of 1 in 10, which allows the difference in pressure between the chamber A and... 

Water bath or other temperature control device Pressurized air system with CO2 free and H2O saturated air Carbon dioxide trapping apparatus with Ba(OH)2 solution Flexible tubing non-permeable to CO2 Stoppers equipped with sampling ports Analytical balance ( 0.1 mg)... 

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