Rolling Straight-Edge - High/Low Detector

The High-Low Detector, commonly called a rolling straight edge, is designed for one-person measurement of pavement surface planeness on highways, airport runways, bridge decks, and similar surfaces. As the unit rolls across the pavement, its center indicator wheel detects surface deviations and magnifies them on an easy-to-read vertical scale. The operator can then mark high or low areas directly on the pavement for corrective work.

Key Features

• Measures pavement surface planeness and identifies high and low areas
• One-person operation
• Suitable for highways, airport runways, bridge decks, and other pavement surfaces
• Surface deviations are magnified 16 times for easier interpretation
• Vertical indicator scale graduated in 0.125" / 1mm increments
• Measures high or low deviations up to 0.25" / 6.4mm
• Rectangular aluminum frame provides lightweight rigidity
• Precision ball-bearing wheels with neoprene tires
• Wheel scraper blades help maintain measurement accuracy
• Integrated dye-marking system allows problem areas to be marked immediately
• Wheel stands stabilize the unit during calibration, transport, and storage
• 16' configuration incorporates additional aluminum reinforcement for rigidity

Included Items

High-Low Detector rolling straight edge with aluminum frame, front and rear support wheels, center indicator wheel, vertical indicator scale, steering handle with dye-control button, dye-can mounting system, scraper blades, and stabilizing wheel stands. 

Typical Applications

Pavement smoothness evaluation, highway construction inspection, airport runway inspection, bridge-deck evaluation, paving QC, identification of areas requiring grinding or filling, DOT pavement inspection, and verification of finished pavement surfaces.

Lab Manager's Tip

Keep the wheels and scraper blades clean before beginning a pavement survey. Material buildup on the wheels can directly affect the indicated surface profile. The rolling straight edge is particularly useful for immediately locating and marking isolated high or low areas rather than generating a full electronic pavement profile. Shipping charges will be higher due to unusual dimensions.