Abstract: A porosimeter evaluates the porosity characteristics (specifically, pore volume, pore distribution and liquid permeability) of a porous sample of material. The porosimeter includes a fluid reservoir located below the sample, and a penetrometer comprising a vessel which catches any fluid displaced from the reservoir of fluid, wherein a level of fluid rises in the penetrometer when additional fluid enters the penetrometer. The sample is preferably wetted, with the same type of fluid which is in the reservoir, prior to placing the sample on the porosimeter. The porosimeter preferably also includes a membrane located between the sample and the reservoir of fluid. The membrane has pores with a size smaller than any of the sample pores. Pore volume of the sample is determined by measuring the change in fluid level in the penetrometer after pressure, which is above the bubble point pressure of the sample but below the bubble point pressure of the membrane, is applied to the sample.

Abstract: A method of determining the pore structure of the individual layers in a multi-layered composite porous material includes the steps of providing a sample of a multi-layered porous material, sealing the sample in suitable test chamber, filling the pores of the sample material with a wetting liquid, such that the liquid/sample surface free energy is less than the gas/sample surface free energy, using a non-reacting gas to apply pressure to one side of the sample sealed in the test chamber, increasing the gas pressure gradually, so as to displace the liquid from the pores, and increase gas flow through the sample, measuring the pressure at which liquid flows from each successive layer of the sample material, and calculating the pore structure using an equation selected from the group consisting of p=&ggr;(dS/dV), D=4&ggr;/p, and f=−d[100(Fw/Fd)]/d D.

Abstract: An improved sample holder for permeable materials, especially useful in permeameters. The sample holder contains the sample within a pliant sleeve. The sleeve is itself constained within a constrictor. When pressed into a seat, the constrictor reduces in diameter evenly along its length, holding the sample in the sleeve tightly without gaps for fluid leakage.

Abstract: A remotely contollable, motorized valve suitable for microprocessor control. The valve is protected against over-closure by a technique of current sensing of motor current. Starting surges are ignored through the use of a timing circuit. The valve may be re-started in the event of mid-travel stoppage, but is still protected against damage due to such stoppage, by permitting manual reset after the valve is stopped.

Abstract: A mercury instrusion type porosimeter arrangement wherein a vessel containing the mercury used for intrusion is disposed such that a conduit issuing therefrom extends downwardly to enable mercury to flow through the action of gravity. The conduit extends to a chamber which contains the sample of material whose porosity characteristics are to be determined and to the tube of a penetrometer assembly which contains the mercury whose height is to be measured, the penetrometer assembly comprising a tube and an electrically actuated transducer associated therewith which senses the height of the mercury in the tube. With this arrangement, there is eliminated the need to introduce atmospheric pressure to force mercury into the penetrometer tube, thus eliminating an initial pressure error. There is, thereby, enabled the precise measurement of the porosity characteristics of materials with larger pores, heretofore unattainable.

Abstract: A porosimeter comprises a tube of non-magnetic material connected at one end to a sample chamber capable, like the tube, of withstanding high internal pressures, means to exhaust the sample chamber and tube, means to fill the chamber and tube with mercury, means to deliver to the tube under adjustable pressure a fluid of density different from that of mercury, a float of magnetic material and of intermediate density disposed in the tube, and a differential transformer in which the float acts as a core to indicate the position of the float.