Gas Permeability Tester for Porous Ceramics and Rocks

What is the Gas Permeability Tester for Porous Ceramics and Rocks?

A test system that forces gas through a cylindrical core or ceramic sample at controlled confining and differential pressure, then calculates Darcy permeability from flow rate. It suits refractories, catalyst supports, reservoir rock plugs and porous ceramics requiring permeability values.

Overview

A gas permeability tester holds a cylindrical plug, typically 25 or 38 mm in diameter, in a rubber sleeve inside a core holder and applies radial confining pressure to prevent bypass flow. Nitrogen or air flows axially under a controlled upstream pressure, and mass flow controllers or bubble flow meters measure the rate at the outlet. Darcy permeability is calculated from flow rate, sample length, area, gas viscosity and mean pressure, with optional Klinkenberg correction for low-permeability rocks. Ranges extend from about 0.01 millidarcy to 10 darcy. The instrument also supports refractory permeability tests and ceramic pore structure studies. Nitrogen is preferred to air to avoid humidity effects, and temperature should be recorded.

How does it work?

Mercury porosimetry exploits the fact that mercury does not wet most solids, so it enters pores only under pressure. The Washburn equation relates the applied pressure to the pore throat diameter, D = −4γcosθ/P, using a surface tension of 485 mN/m and a contact angle of about 130°. Pressure is increased stepwise from vacuum to 400 MPa while the intruded volume is recorded by a capacitance dilatometer, and extrusion on depressurization shows pore connectivity. Capillary flow porometry instead wets the sample with a low surface tension liquid and records the gas pressure needed to blow liquid from pores, giving through-pore size. Gas permeability systems measure flow through a sample at a known pressure difference, and helium pycnometers determine skeletal volume.

What are the key features?

• Hassler-type core holder with adjustable confining pressure
• Mass flow controllers covering low to high flow ranges
• Differential pressure sensors with automatic range switching
• Klinkenberg correction software for low-permeability plugs
• Adapters for 25 mm, 38 mm and custom sample diameters
• Automatic calculation and reporting in millidarcy, darcy and m²

What are the technical specifications?

A typical gas permeability tester for porous ceramics and rocks configuration offers permeability range of 0.01 mD–10 D, sample diameter of 25 mm, 38 mm (others optional), sample length of 10–80 mm, confining pressure of Up to 10 MPa, upstream pressure of 0–1 MPa and flow measurement range of 0.01–5000 mL/min. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Gas Permeability Tester for Porous Ceramics and Rocks is used in reservoir core plug analysis, refractory and kiln furniture testing, catalyst support and filter ceramics and cement and concrete gas permeability. Across the wider Porosimeters class, laboratories also deploy it for ceramic and refractory pore analysis, filter and membrane pore size testing and catalyst pellet macropore distribution.

Which standards and certifications apply?

Relevant standards and methods include ISO 15901-1, ASTM D4284, ASTM D4404, ASTM F316 and ASTM D6226. Certification candidates for this model are CE and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Mercury instruments need containment for vapor and spills, a dedicated sink or waste procedure, and staff training under local regulations. Samples must be dried and sized to fit penetrometers, and results depend on the assumed contact angle and surface tension. Correct for mercury compression and penetrometer expansion with blank runs. Calibrate pressure transducers annually and verify with a reference material of known pore size. Capillary flow systems need wetting liquids with documented surface tension and clean, dry gas. Place high-pressure units on a rigid bench and follow pressure vessel inspection rules.

How do I select the right Gas Permeability Tester for Porous Ceramics and Rocks?

Select this variant when permeability, not pore size, is the specification, such as for rock cores, refractories or ceramic filter supports. It does not provide pore size distributions. In an RFQ, specify sample diameters, permeability range, confining pressure, gas type and whether Klinkenberg correction is required.

How does it compare with other Porosimeters variants?

Choose by pore size range, sample form and the quantity that the specification reports. Mercury intrusion covers a broad span, about 3.6 nm to 400 µm, and suits rigid ceramics, rocks, cement and catalysts pellets. It is unsuitable for compressible or amalgamating samples and requires mercury handling controls. Capillary flow porometers suit membranes and filters where through-pore bubble point and mean flow pore size are required. Gas permeability testers give Darcy permeability of rocks and ceramics. Helium pycnometers supply true density and closed porosity. Check the number of high-pressure ports, maximum pressure, penetrometer volume options, automation, and whether reporting follows ISO 15901-1, ASTM D4284 or ASTM F316.