Benelux Scientific
Porolux® 1000
The POROLUX™ 1000 series uses the pressure step/stability method to measure pore diameters. The inlet valve for the gas is a large, specially designed needle valve that is opened with very accurate and precise movements. To increase pressure, the valve opens to a precise point and then stops its movement. The pressure and flow sensors will only take a datapoint when the used defined stability algorithms are met for both pressure and flow. In this way, the POROLUX™ 1000 detects the opening of a pore at a certain pressure and waits until all pores of the same diameter are completely opened before accepting a datapoint. This results in very accurate measurement of pore sizes and allows a calculation of the real pore size distribution. The POROLUX™ 1000 comes with pressure transducers up to 35 bar, allowing minimum pore size measurements down to 18 nm (1). This series also comes with extended options such as multiple bubble point detection algorithms, liquid permeability, hydrohead and special sample holders for hollow fibers, large samples, etc.
One of the most important parameters measured by a porometer is the first bubble point or FBP. This point defines the largest pores present inside the material. ASTM F-316 defines the FBP as the pressure at which the first continuous bubbles are detected. In the calculated FBP operating mode, the POROLUX™ 1000 can define the FBP at different flows, e.g. at 30, 50, 100 ml/min. Because with this approach there is already flow at the FBP. And therefore, by this definition, this calculated FBP is always smaller than the real bubble point and thus the calculated FBP never represents the real opening of the largest pores.
The POROLUX™ 1000 can also be operated in the measured bubble point mode for detecting the actual largest pore present. In the POROLUX™ the fully wetted sample and sample chamber all the way up to the needle valve form a closed system. Therefore, if we increase the pressure on the sample using a small, constant flow of gas towards the sample chamber, the pressure will slowly increase. As the volume is fixed, this constant flow will result in a linear rise of the pressure above the sample. At the moment the first and largest pore is opened, there will be a change in the linear pressure increase. This chance can be regarded as the true first bubble point of the material. This method to measure the FBP shows an excellent reproducibility.
In the log-in section you can find more details about the unique features of the POROLUX™ 1000.
The POROLUX™ 1000 can also be operated in the measured bubble point mode for detecting the actual largest pore present. In the POROLUX™ the fully wetted sample and sample chamber all the way up to the needle valve form a closed system. Therefore, if we increase the pressure on the sample using a small, constant flow of gas towards the sample chamber, the pressure will slowly increase. As the volume is fixed, this constant flow will result in a linear rise of the pressure above the sample. At the moment the first and largest pore is opened, there will be a change in the linear pressure increase. This chance can be regarded as the true first bubble point of the material. This method to measure the FBP shows an excellent reproducibility.
In the log-in section you can find more details about the unique features of the POROLUX™ 1000.
