- Densometers are the accepted standard for measuring the porosity of materials such as papers, wovens, plastics and membranes.
- All Densometers measure the time required for a given volume and of air (25cc to 400cc) to flow through a standard area of material being tested under light uniform pressure.
- Certain models, such as the S-P-S Tester, are also used to measure surface smoothness and material softness.
- Manual and automatic units available. Conform to TAPPI T-460, ASTM D-726-58 & APPITA/AS 1301-420, BS 5926, CPPA D-14, ISO 5636/5, D-202-77, SCAN P-19 & P-53.
The Densometer test measures the time required for a given volume of air (25cc to 300cc) to flow through a standard area of material tested, under light uniform pressure. The air pressure is supplied by an inner cylinder of specific diameter and standardized weight, floating freely within an outer cylinder partly filled with oil to act as an air-seal. The sample material is held between clamping plates having a circular orifice area of 1.0 (standard), 0.25 or 0.1 square inch (optional).
Densometer readings may be evaluated on both a direct or indirect basis dependent upon the material and test purpose. They are a direct test of materials which are intended to either resist or permit the passage of air. Indirectly, they are used to measure other physical properties which affect the flow of air through a porous sheet.
- In manufacturing and printing, to control the selection of materials affording the appropriate degree of liquid (ink, varnish, sizing) absorption.
- To test filters, porous bags & materials where controlled porosity is essential.
- To test insulating materials for air resistance.
- To supplement other physical tests enabling regulation or strength of manufacturing process to give the desired formation, appearance or strength since there is a close correlation in a given material between air permeability and these other properties.
The No. 4190 was originally developed to test the printing quality of paper. In more recent years, its use has spread to other industries in testing or checking other material surfaces for smoothness, softness or porosity. In dealing with the printability of paper, it has been found that smoothness is the most important factor in printing quality and softness is usually secondary.
The Gurley No. 4190 S-P-S Tester measures a given air flow through the sample for porosity tests and leakage across its surface(s) for softness or smoothness tests. This is accomplished by changing a variety of adapter and clamping plates.
This model is identical to the No. 4110 and 4140 for porosity tests and their components. Additionally, it includes a 0.34 lb. weight, smoothness test clamping plate, softness test clamping plate, punch and accessory storage box. Both the automatic digital timer and instrument base are recommended and should be ordered separately.