Capillary Flow Porometer

capillary flow porometer productThe Capillary Flow Porometer from PMI Porous Materials, Inc., is a good example to illustrate the specialisation available within pore size instrumentation. Meritics has been highly impressed by the quality of PMI’s innovations and this particular model has proved very popular with users.

The analyses it carries out are fully automated and include measurement of the bubble point, distribution of pore size, mean flow pore size, hydro-head and integrity, as well as liquid, gas, Frazier, Gurley, and Rayl permeability.

Versatility is one of its key qualities. Samples can be tested under compression, tension or elevated temperature. In other words, the conditions in which the material will function can be simulated.

It has been especially welcome as a tool in quality control and R&D departmentss, where its non-destructive operation, ease of use and minimal need for maintenance are invaluable.

The method it uses can be summarised as follows. A fully wetted sample of the material is placed in the sample chamber, which is then sealed. Gas is then passed into the chamber behind the sample. At a certain point, the pressure reaches a level just sufficient to overcome the capillary action of the fluid in the largest pore. This is the bubble point.

Having determined the bubble point, the pressure is increased, while measuring flow rate, until all of the pores are empty and the sample is considered dry. Then measurements of gas pressure and flow rate through the dry sample can be taken. A variety of further measurements may be computed from the data obtained in this way.

The Capillary Flow Porometer will accommodate a wide range of materials and sample sizes. It can even measure the gas permeability of samples which are almost impermeable (microflow permeability).

Compatible with Windows 95 and higher, its Windows-based software takes care of all control, measurement, data collection and report generation functions. However, the option of complete manual control is also available if the user prefers.

With its transparent sample chamber, users can monitor progress visually. Meanwhile, a real-time graphical test display gives constant information on testing status and results throughout the analysis. The time taken for each test is a mere 10 minutes.

The following non-exhaustive list of industries and materials for which this instrument has been used gives some idea of its value:  automotive, chemical and environmental, non-wovens, ceramics, battery separators, filter media, paper, fuel cells, biotechnology and healthcare, food and beverages, pharmaceuticals and textiles.