Touch-screen Geotextile Apparent Opening Size (AOS) Tester - QualiGTX™ AOS T
QualiGTX™ AOS T geotextile apparent opening size tester determines the characteristic pore size of single-layer geotextiles and related geosynthetic products using the dry sieving principle. Civil engineering laboratories, geosynthetics manufacturers, and highway quality-control departments rely on this measurement to confirm that a filter fabric retains soil while still passing water. The instrument handles every common geotextile type, from needle-punched nonwovens to woven monofilament fabrics. A color touchscreen controls the full sieving cycle from a single panel.
Five specimen pressing rings ship with the QualiGTX™ AOS T, so a technician stacks and runs five samples in one cycle instead of repeating the test one fabric at a time. The 200 mm sieve column accepts up to 400 mm of stacked frames. A low-noise drive keeps sound levels manageable in shared laboratory space. A graded glass bead set arrives with the unit, so the lab starts testing without sourcing reference media separately.
Repeatable agitation separates a usable opening size result from a questionable one. The tester holds horizontal oscillation at 221 cycles per minute and vertical tapping at 147 impacts per minute, with a fixed 8 mm amplitude and a 12.5 mm radius of gyration. Those settings stay constant across operators and shifts, which keeps O95 values comparable between production lots and between laboratories. The result feeds directly into filter design decisions on drainage, separation, and erosion-control projects.
