The HM-574 Benkelman Beam is a simple lever-arm device which measures deflection of flexible pavements under the action of moving wheel loads. The probe beam, supported by a rigid reference beam, measures deflections using its 2.44m (8ft) probe end and a 1.22m (4ft) dial indicator on the other side of the fulcrum. Deflections measured on a dial indicator are doubled to obtain total pavement deflection. The probe beam is placed between the tires of a test vehicle and deflection is measured as the vehicle passes over the test area. The reference beam has a leveling adjustment to zero the dial indicator. A switchable battery-operated vibrator alerts operator and assures free movement of beam parts during measurements.
The three-piece, anodized, lightweight aluminum beam is 33lb (15kg) net weight for easy portability, and the longest piece is 6.5ft (1.99m). Mechanical or Digital Dial Indicators must be ordered separately.
- Measures deflection of flexible pavements under the action of moving wheel loads
- Features a leveling adjustment to easily zero the dial indicator
- Assures free movement of beam parts during measurements
- Has a lightweight frame for portability