Operating Principle and Energy-Loss Physics
The Quali-FSRT™ 303 Skid Resistance and Friction Tester measures surface slipperiness by recording the kinetic energy lost when a calibrated rubber slider sweeps across a test path at approximately 10 km/h. Operating on an energy-loss principle, the instrument converts potential energy into kinetic momentum as the swinging arm drops from its horizontal release point.
When the 16 g rubber slider pad contacts the test surface, friction converts kinetic momentum into heat and rubber deformation flex. Slipperier ground absorbs less momentum, allowing the pendulum to swing higher, whereas rougher ground pulls harder on the slider pad to reduce upward swing height. A low-friction trailing pointer catches the maximum height mark on the scale, giving a direct reading in British Pendulum Number (BPN), Pendulum Test Value (PTV), or 'F' Scale units.
Measurement Sequence & Energy-Loss Workflow
- Pendulum Release: Unlatch the Quali-FSRT™ 303 arm from its horizontal starting hook.
- Surface Impact: The calibrated rubber slider pad strikes the surface patch at approximately 10 km/h.
- Contact Scrape: The rubber pad drags across a fixed 126 mm or 76 mm stroke length.
- Energy Dissipation: Surface friction converts kinetic momentum into heat and rubber flexing work.
- Post-Contact Swing: The arm continues its upward arc past the contact zone with reduced energy.
- Pointer Capture: A low-friction trailing pointer needle captures the maximum upward height.
- Scale Output: Read the direct friction score on the dial (BPN, PTV, or 'F' Scale).
Figure 1: Dynamic energy-loss workflow and measurement sequence on the Quali-FSRT™ 303.
Mechanical precision is maintained by a 1500 ± 30 g rocker arm positioned 410 ± 5 mm from its center of gravity, delivering a constant 22.2 ± 0.5 kN positive static pressure onto the test surface.
Standardized Test Methodology and Parameters
Testing with the Quali-FSRT™ 303 follows a structured, standardized procedure to ensure repeatable friction measurements across laboratory and field applications.
| Operating Feature | Quali-FSRT™ 303 Factory Specification | Standard Application |
|---|
| Governing Standards | ASTM E303, BS EN 13036-4, BS 7976, AS/NZS 4586, BS EN 1097-8, BS 812 Pt 144 | Field pavement audits, indoor floor slip checks, and laboratory aggregate testing |
| Slider Pad Variants | Slider 55 (Road surfaces) / Slider 96 (Four S) (Indoor floors) / Small Slider (PSV) | Matches rubber pad stiffness to asphalt, pedestrian tiles, or polished rock aggregate samples |
| Contact Stroke Length | 126 mm (Pavement / Flooring) or 76 mm (Aggregate PSV) | Adjusted via the included Perspex setting gauge |
| Dual Scale System | Main Dial (BPN / PTV scale) + Built-in 'F' Scale | Direct reading for standard field paths and short-stroke PSV lab tests |
| Hardware Setup | Levelling base, 3 adjustment feet, soft-ground pads, 1500 g rocker arm | Maintains consistent 22.2 kN contact pressure on soft soil or rigid concrete |
Figure 2: Quali-FSRT™ 303 operational parameters and configuration options.
Step-by-Step Execution Protocol
- Surface Clearing: Loose dirt and grit are swept clear using the included surface cleaning brush.
- Instrument Levelling & Path Calibration: The base is leveled using the three adjustable feet. The contact path length (126 mm for standard surfaces or 76 mm for PSV aggregate samples) is calibrated using the Perspex setting gauge.
- Wet or Dry Condition Setup: For wet testing (ASTM E303 / BS EN 13036-4), clean water is applied across the contact path using the supplied spray bottle. For dry pedestrian floor testing (BS 7976 / AS/NZS 4586), the surface remains dry.
- Swing Execution & Averaging: The operator releases the pendulum arm five consecutive times. The first swing reading is discarded, and the average of the remaining four drops defines the final BPN, PTV, or 'F' Scale score.
- Temperature Adjustments: Standard mathematical temperature corrections compensate for rubber pad stiffness changes across varying ambient field temperatures.
