Temperature-Controlled Geotextile Permeability Tester - QualiGTX™ GPT T
QualiGTX™ GPT T geotextile permeability tester measures vertical water flow through geotextiles and related products under no-load conditions, with test water held between 10 °C and 60 °C. Qualitest North America specified the thermostatic circuit because water viscosity changes with temperature, and an uncontrolled bath adds scatter that specimen replication cannot remove. The control computer positions the head, times the run, and calculates the vertical permeability coefficient. Operators receive a report ready to upload or print.
Geosynthetics manufacturers, civil engineering laboratories, and construction QC groups use the QualiGTX™ GPT T to verify filter and drainage fabrics before installation. A 304 stainless steel clamp holds a 50 mm specimen up to 20 mm thick, and the operator sets any head height up to a 250 mm differential. The system finds the zero water level on its own, then holds level through a metered water supply rather than an overflow weir. A dissolved oxygen analyzer checks water quality before measurement begins.
An automated 70 mm head differential sequence carries the test through the 0.8 to 0.2 head range without operator intervention, and timing resolves to 0.1 s. A 36 L stainless steel tank, PID temperature loop, and 15 L/min circulation pump hold conditions steady through the run. Temperature readings correct to ±0.1 °C, which feeds the viscosity correction applied to the final result. The cabinet spans 1,150 mm and fits standard laboratory floor space.
