Can I use permeability or hydraulic conductivity data to derive a void structure?

No. Permeability or hydraulic conductivity is too sensitive to too many features of the void structure, so 'inversion' of that property is not possible. Also, a single permeability or hydraulic conductivity reading contains too little information. A single measurement from the mercury intrusion curve (e.g. the characteristic throat diameter) also provides too little information, which is why PoreXpert uses the shape of the entire curve.

 

Can PoreXpert read data files direct from my porosimeter or porometer?

Yes. PoreXpert reads data direct from Micromeritics Autopore, ThermoFisher (Carlo Erba) Pascal, Quantachrome porosimeters and the PoroluxTM 100 or 1000 Porometer. For further details on file formats, see Experimental File Formats in this Help system.

 

Why do I need PoreXpert when I already have the Manufacturer's porosimeter software?

The Manufacturer's software uses an implicit assumption that the porous solid comprises unconnected aligned cylinders, as in the 'Not this' diagram which opens the website. If your sample is like that, then use the Manufacturer's software. If it is more like the 'But this' diagram, i.e. a 3-D interconnected network of voids and narrower connections, then PoreXpert will give you more information. PoreXpert can use both models to interpret the experimental data as shown below.

                                 

Not This        But This  

 

The Micromeritics and ThermoFisher software calculates fractal dimensions, whereas PoreXpert does not. Why not?

First you need to read the previous answer. Then the answer to this is that whereas a fractal dimension can be calculated based on the aligned cylinders model, it is very much more difficult for a 3-D interconnected network, and we have not done it yet.

 

Can I use PoreXpert for quality assurance purposes?

Yes. Imagine a box bounded by acceptable upper and lower limits of two experimental parameters. The box is two-dimensional for 2 parameters, but for more parameters becomes a cuboid, and so on. If your product's properties fall within the box, then it is acceptable for sale. PoreXpert allows you to use more and/or better parameters to define the box. For example, you could replace characteristics throat diameter, which is based on the 50% intrusion point, with simulated permeability, which may be much closer to a required experimental property. We have done this for tantalum capacitors made from sintered tantalum corals - the efficiency of the final capacitors correlated closely with PoreXpert simulated permeability. A case study with more detail will be produced about this.

 

While working with PoreXpert program, an error occurred with a data file. Error message was like 'second data is lower than first data'?

The software will not accept intrusion curves for which the intrusion volume goes down with increasing pressure. This sometimes happens if the user has not used the PoreXpert compressibility corrector to pre-process the data using an accurate blank run for the same penetrometer. So under those circumstances, you must clean up the data file - i.e. remove the values which go down instead of up.

 

Can I model both mercury intrusion and extrusion, or both water retention and drainage?

No - unfortunately PoreXpert only fits itself to a mercury intrusion curve, water retention curve or porometry data. We have not managed to fit both intrusion and extrusion together yet (or water retention followed by drainage).

 

The PoreXpert program did not get a value of porosity from Micromeritics *.rpt, or Quantachrome *.prm file. I read it from a report and wrote it in the data input screen. Is this operation valid?

 

Yes - for Micromeritics and Quantachrome format files the software does not read the porosity directly, so must be input manually. However, if the intrusion files and the blank are processed first using the compressibility corrector for Micromeritics files, the correct porosity is calculated.